Basic IT Revision PDF

Revision for Basic IT Chapter 1: INTRODUCTION TO COMPUTER Today s technology Because technology changes, you must keep up with the changes to remain digitally literate–having a current knowledge and understanding of computers, mobile devices, the web, and related techno...

Revision for Basic IT Chapter 1: INTRODUCTION TO COMPUTER Today s technology Because technology changes, you must keep up with the changes to remain digitally literate–having a current knowledge and understanding of computers, mobile devices, the web, and related technologies ’ Computers A computer is an electronic device, operating under the control of instructions stored in its own memory Three steps: -Accepts date for input -Processing -Produces information (output) The Components of a Computer A computer contains many electric, electronic, and mechanical components known as hardware. Input Device: Allows you to enter data and instructions into a computer 1 Output Device: Hardware component that conveys information to one or more people System Unit Case that contains the electronic components of the computer that are used to process data Storage Device: Records (writes) and/or retrieves (reads) items to and from storage media Communications Device: Enables a computer to send and receive data, instructions, and information to and from one or more computers or mobile devices 2 Advantages and Disadvantages of Using Computers Advantages of Using Computers: -Speed -Reliability -Consistency -Storage -Communications Disadvantages of Using Computers: -Health Risks -Violation of Privacy -Public Safety -Impact on Labor Force -Impact on Environment Categories of Computers -Personal computers -Mobile computers and mobile devices -Game consoles -Servers -Mainframes -Supercomputers -Embedded computers 3 Personal Computers A personal computer can perform all of its input, processing, output, and storage activities by itself Two popular architectures are the PC and the Apple -Desktop computer Mobile Computers and Mobile Devices -Personal computer you can carry from place to place -Examples include notebook computers, laptop computers, netbooks, ultra-thins, and Tablet PCs -Computing device small enough to hold in your hand -Examples include smart phones and PDAs, e- book readers, handheld computers, portable media players, and digital cameras 4 Notebook, Laptop & Tablet Laptop: Notebook computer, a thin, lightweight mobile computer with a screen in its lid and a keyboard in its base. Tablet: A thin, lighter – weight mobile computer that has a touch screen. Smartphones An Internet – capable phone that usually also includes a calendar, an address book, a calculator, a notepad, games, and several other apps. Digital Camera A digital camera is a device that allows you to take photos and store the photographed images digitally. Portable and digital media players -Is a mobile device on which you can store, organize, and play or view digital media. -Digital media includes music, photos, and videos. E – book Readers An e–book reader, or e–reader, is a mobile device that is used primary for reading 5 e–books Wearable Devices Is a small, mobile computing consumer device designed to be worn. Game Consoles A game console is a mobile computing device designed for single- player or multiplayer video games Servers A server controls access to the hardware, software, and other resources on a network – Provides a centralized storage area for programs, data, and information Mainframes A mainframe is a large, expensive, powerful computer that can handle hundreds or thousands of connected users simultaneous Supercomputers A supercomputer is the fastest, most powerful computer -Fastest supercomputers are capable of processing more than one quadrillion instructions in a single second 6 Data and Information Input: Cashier scans or enters items purchased and the amount received from the customer. Storage & Process: The computer receives the entered data, stores it, processes the data into information (the receipt), and store the resulting information Output: The resulting information (the cash register receipt) is printed for the customer. 7 Data and Information A scanner is a light-sensing input device that converts printed text and images into a form the computer can process -An output device is any hardware component that conveys information from a computer or mobile device to one or more people -A printer is an output device that produces text and graphics on a physical 8 medium, such as paper or other material -A display is an output device that visually conveys text, graphics, and video information Speakers allow you to hear audio such as music, voice, and other sounds – Earbuds – Headphones Memory and Storage -Memory consists of electronic components that store instructions waiting to be executed and the data needed by those instructions -A computer keeps data, instructions, and information on storage media -A storage device records (writes) and/or retrieves (reads) items to and from storage media 9 The web The Internet is a worldwide collection of computer networks that connects millions of businesses, government agencies, educational institutions, and individuals -The World Wide Web (or web, for short) is a global library of information available to anyone connected to the Internet -The web consists of a worldwide collection of electronic documents, each of which is called a webpage -A website is a collection of related webpages -A web server is a computer that delivers requested webpages to your computer 10 11 Digital Safety and Security It is important that users protect their computers and mobile devices -Viruses and Other Malware -Privacy -Health Concerns -Environmental Issues Programs and Apps Software, also called a program, tells the computer what tasks to perform and how to perform them System Software Operating system Tools Applications Installing a program is the process of setting up the program to work with the computer, mobile device, printer, and/or other hardware Once installed, you can run a program so that you can interact with it You interact with a program through its user interface Communications and Networks 12 A communications device is hardware capable of transferring items from computers and devices to transmission media and vice versa Examples of wireless communications technologies include: -Wi-Fi -Bluetooth -Cellular radio -A network is a collection of computers and devices connected together, often wirelessly, via communications devices and transmission media Technology users -Home User -Small/Home Office User -Mobile User -Power User -Enterprise User Computer Literate -You can avoid falling prey to hackers and viruses because you are aware of how they operate -You know how to protect yourself from identity theft -You can separate the real privacy and security risks from things you 13  don t have to worry about. -You know how to find information and use the web effectively -You can avoid being overwhelmed by spam, adware and spyware ’ -You know how to diagnose and fix problems with your hardware and software Group discussion 1 -Discuss how technologies are used in the following sectors: Government Finance Retail Entertainment Health Care Science Travel Publishing Manufacturing Chapter 3-4: UNDERSTANDING INPUT AND OUTPUT (PART 1) What is Input? Input is any data and instructions entered into the memory of a computer. Input: Data (collection of unprocessed items) entered into the memory Process: Once data is in memory, it will be interpreted and executed. 14 Output: Executes instructions to process the data into information Instructions: software, commands, and user responses Software A series of related instructions, organized for a common purpose that tells a computer or mobile device what task to perform and how to perform them. Command An instruction that causes a program or app to perform a specific action. User response An instruction a user issues by responding to a message displayed by a program or app. Commonly used input methods include: Keyboard Pointing devices Touch screens Pen input Motion input Voice input Video input Scanners and reading devices Keyboards A keyboard is an input device that contains keys users press to 15  enter data and instructions into a computer or mobile device Most desktop computer keyboards have… Between 101 and 105 keys A numeric keypad on the right side of the keyboard Function keys, CTRL keys, ALT keys, and arrow keys Windows key Application key Toggle keys Try to change your laptop keyboard setting to Dvorak To enable Dvorak on Windows 7, open the Region and Language window from the Control Panel, click the Keyboards and Languages tab, and click the change Keyboards button. Click Add, expand the English (United States) section, and add a Dvorak layout. You can then switch your active keyboard Changing the keyboard layout in Windows 8 and 10 – Open Control Panel. – Under the Clock, Language, and Region section, click Change input methods. – Click the Options link for your keyboard. – Click Add an input method. – Select the Dvorak layout you want to use. The Keyboard The insertion point, also known as the cursor, is a symbol on the screen that indicates where the next character you type will appear 16  An ergonomic keyboard has a design that reduces the chance of repetitive strain injuries of wrist and hand Ergonomics incorporates comfort, efficiency, and safety in the design of the workplace Pointing Devices A pointer is a small symbol on the screen whose location and shape change as a user moves a pointing device Mouse: A mouse is a pointing device that fits under the palm of your hand comfortably -Optical Mouse -Laser Mouse -Touch Mouse Touchpad: A touchpad is a small, flat, rectangular pointing device that is sensitive to pressure and motion Trackball: A trackball is a stationary pointing device with a ball on its top or side Touch Screens 17  A touch screen is a touch-sensitive display -Desktop Monitors and screens on laptops and tablets Smartphones Wearable Devices Portable Media Players Digital Camera Kiosk Navigation Systems Pen Input With pen input, you touch a stylus or digital pen on a flat surface to write, draw, or make selections Digital pen is slightly larger than a stylus, is an input device that captures and converts a user s handwriting or drawing into a digital format, which users an upload (transfer) to a computer or mobile device. ’ A graphics tablet, also called a digitizer, is an electronic plastic board that detects and converts movements of a style or digital pen into signals that are sent to the computer Motion, Voice, and Video Input With motion input, sometimes called gesture recognition, users can guide on-screen elements using air gestures 18  Voice input is the process of entering input by speaking into a microphone Voice recognition, also called speech recognition, is the computer or mobile device s capability of distinguishing spoken words Audio input is the process of entering any sound into the computer such as speech, music, and sound effects ’ Music production software allows users to record, compose, mix, and edit music and sounds Video input is the process of capturing full-motion images and storing them on a computer or mobile device s storage medium Webcam enable us to: – Capture video and still images ’ – Send email with video attachments – Broadcast live video or images – Conduct videoconferences – Make video calls A videoconference is a meeting between two or more geographically separated people Digital Cameras A digital camera is a mobile device that allows users to take 19  pictures and store them digitally -Studio cameras -Field cameras -Point-and-shoot camera Two factors affect the quality of digital camera photos:- Resolution: Resolution is the number of horizontal and vertical pixels in a display device A pixel is the smallest element in an electronic display Number of bits stored in each pixel: Each pixel consists of one or more bits of data The more bits used to represent a pixel, the more colors and shades of gray that can be represented Scanners and Reading Devices: A scanner is a light-sensing input device that reads printed text and graphics and then translates the results into a form the computer can process – A flatbed scanner Optical Reader is a device that uses a light source to read characters, marks and codes and then converts them into digital data. -Optical Character Recognition (OCR) 20 -Optical Mark Recognition (OMR) -Bar Code Reader -R Code Reader RFID (radio frequency identification) uses radio signals to communicate with a tag placed in or attached to an object An RFID reader reads information on the tag via radio waves 21 22 Chapter 5: TYPE OF STORAGE Storage: Storage holds data, instructions, and information for future use. A storage medium is the physical material on which a computer keeps data, information, programs, and applications. A storage device is the hardware that records and/or retrieves items to and from storage media. (is coming out in exam) Reading is the process of transferring items from a storage medium into memory. Writing is the process of transferring items from memory to a storage medium. Access time measures: – The amount of time it takes a storage device to locate an item on a storage medium. – The time required to deliver an item from memory to the processor. Transfer rate is the speed with which data, instructions and information transfer to and from a device. Hard drives: A hard disk, also called a hard disk drive (HDD) contains one or more inflexible, circular platters that use magnetic particles to store data, instructions, and information. Hard disks can store data using longitudinal recording or perpendicular recording. 23 Characteristics of a hard disk nclude: 1. Capacity 2. Platters 3. Read/Write Heads 4. Track/Cylinders 5. Sectors 6. Revolutions per Minute (how many times the discspins in a minute) 7. Transfer Rate 8. Access Time Formatting is the process of dividing the disk into tracks and sectors. A head crash occurs when a read/write head touches the surface of a platter Always keep a backup of your hard disk An SSD (solid state drive) is a flash memory storage device that contains its own processor to manage its storage An SSD (solid state drive) has several advantages over traditional (magnetic) hard disks: -Faster access times -Faster transfer rates -Quieter operation -More durable -Lighter weight 24 -Less power consumption -Less heat generation -Longer life -Defragmentation not required Hard Disks An external hard disk is a separate free-standing hard disk that connects to your computer with a cable or wirelessly A removable hard disk is a hard disk that you insert and remove from a drive Internal and external hard disks are available in miniature sizes (miniature hard disks) Flash Memory Storage Flash memory chips are a type of solid state media and contain no moving parts Solid state drives (SSDs) have several advantages over magnetic hard disks:- -Faster access time -Faster transfer rates -Generate less heat and consume less power -Last longer A memory card is a removable flash memory device that you insert and remove from a slot in a computer, mobile device, or card reader/writer -CompactFlash (CF) 25 -Secure Digital (SD) -Secure Digital -High Capacity (SDHC) -microSD -microSDHC -xD Picture Card -Memory Stick -Memory Stick Micro (M2) USB flash drives plug into a USB port on a computer or mobile device Cloud Storage 26  Cloud storage is an Internet service that provides storage to computer or mobile device users Users subscribe to cloud storage for a variety of reasons: Access files from any computer Store large files instantaneously Allow others to access their files View time-critical data and images immediately Store offsite backups Provide data center functions Optical Discs An optical disc consists of a flat, round, portable disc made of metal, plastic, and lacquer that is written and read by a laser (CD) 27 Other Types of Storage A magnetic stripe card has a magnetic stripe that contains information (insert card inside machine when pay) A smart card stores data on an integrated circuit embedded in the card (scan card top of the machine when pay) The RFID tag consists of an antenna and a memory chip that contains the information to be transmitted via radio waves An NFC-enabled device contains an NFC chip An NFC tag contains a chip and an antenna that contains information to be transmitted (Use phone and wifi to pay “scan phone”) Tape is a magnetically coated ribbon of plastic capable of storing large amounts of data and information A tape drive reads and writes data and information on a tape 28  Microfilm and microfiche store microscopic images of documents on a roll or sheet film (Its like an old projector roller) Enterprise storage stores huge volumes of data and information for large businesses – Uses special hardware for heavy use, maximum availability, and maximum efficiency Chapter 8: FUNDAMENTALS OF THE WORLD WIDE WEB AND THE INTERNET The Internet The Internet is a worldwide collection of networks that connects millions of businesses, government agencies, educational institutions, and individuals Evolution of the Internet The Internet originated as ARPANET in September 1969 and had two 29 main goals: Allow scientists at different physical locations to share information and work together Function even if part of the network were disabled or destroyed by a disaster Connecting to the Internet With wired connections, a computer or device physically attaches via a cable or wire to a communications device Computers can use a wireless modem or other communications device that enables wireless connectivity 30 An access provider is a business that provides individuals and organizations access to the Internet free or for a fee An Internet service provider (ISP) is a business that provides individuals and organizations access to the Internet free or for a fee A hot spot is a wireless network that provides Internet connections 31 to mobile computers and devices An IP address is a sequence of numbers that uniquely identifies each computer or device connected to the Internet A domain name is a text-based name that corresponds to the IP address A DNS server translates the domain name into its associated IP address 32 The World Wide Web The World Wide Web (WWW), or web, consists of a worldwide collection of electronic documents (webpages) A website is a collection of related webpages and associated items A web server is a computer that delivers requested webpages to your computer Web 2.0 refers to Web sites that provide a means for users to interact A browser is an application that enables users with an Internet connection to access and view webpages on a computer or mobile device A webpage has a unique address, called a web address or URL A home page is the first page that a Web site displays Web pages provide links to other related Web pages – Surfing the Web 33  Downloading is the process of receiving information Some Web pages are designed specifically for microbrowsers Tabbed browsing allows you to open and view multiple Web pages in a single Web browser window Types of websites Search engine Online social network Informational and research Media sharing Bookmarking News, weather, sports, and other mass media Educational Business, governmental, and organizational Blogs Wiki and collaboration Health and fitness Science Entertainment Banking and finance Travel and tourism Mapping Retail and auctions Careers and employment E-commerce 34  Portals Content aggregation Website creation and management The World Wide Web A set of programs that searches the web for keywords and then returns a list of the sites on which those keywords are found. Two types of search tools are search engines and subject directories Search engine: Finds information related to a specific topic Subject directory: Classifies Web pages in an organized set of categories Strategies in using search engine Search for a phrase – Place quotation marks around your keywords. Search within a specific website – Keyword site: URL of the website Use a wild card – The asterisk (“*”) is a wild card, or placeholder, feature that is helpful when you 35 need to search with unknown terms The World Wide Web Web publishing is the development and maintenance of Web pages Plan a Web site Analyze and design a Web site Create a Web site Deploy a Web site Maintain a Web site E-Commerce E-commerce is a business transaction that occurs over an electronic network M-commerce identifies e-commerce that takes place using mobile devices 36 Other Internet Services Email is the transmission of messages and files via a computer network Instant messaging services notify you when one or more of your established contacts are online and then allows you to exchange messages or files or join a private chat room with them A mailing list is a group of e-mail names and addresses given a single name – Subscribing adds your e-mail name and address – Unsubscribing removes your name A chat is a real-time typed conversation that takes place on a computer or mobile device with many other online users An online discussion is an online area in which users have written discussions about a particular subject VoIP (Voice over IP) enables users to speak to other users via their Internet connection A newsgroup is an online area in which users have written discussions about a particular subject – Typically requires a newsreader A message board is a Web-based type of discussion group FTP (File Transfer Protocol) is an Internet standard that permits file uploading and downloading with other computers on the Internet 37  Many operating systems include FTP capabilities An FTP server is a computer that allows users to upload and/or download files using FTP Safe browsing techniques Verify the website is safe Turn off location sharing Clear your browsing history Never store passwords Use a phishing filter Enable a pop – up or pop – under blocker Use private browsing Use a proxy server How search engines work? 38  The first component is a program called a spider, which constantly collects data on the web, following links in websites and reading web pages. Second component is an indexer program, which organizes data into a large database. The search engine software then searches the indexed data, pulling out relevant information according to your search. Chapter 9: NETWORK THE INTERNET Communications Computer Communication describes a process in which two or more computers or devices transfer data, instructions, and information -Sending device -Transmission media -Receiving device Networks A network is a collection of computers and devices connected together via communications devices and transmission media A local area network (LAN) is a network that connects computers and devices in a limited geographical area A wireless LAN (WLAN) is a LAN that uses no physical wires A metropolitan area network (MAN) connects LANs in a metropolitan area A wide area network (WAN) is a network that covers a large geographic area 39  A personal area network (PAN) is a network that connects computers and devices in an individual s workspace with wired and wireless technology The design of computers, devices, and media on a network is sometimes called the network architecture. ’ 2 types: – Client/server network – Peer-to-peer network Network Architectures 40  Client/Server Network – One or more computers act as a server, the other computers on the network request services from the server. – A server controls access to the hardware, software and other resources on the network. – A clients are the computers that rely on the server for its resources. Peer to peer – P2P network is simple, inexpensive network architecture that typically connects fewer than 10 computers. – Each computer is called a peer. – They have equal responsibilities and capabilities, sharing hardware, data, or information with other computers. Networks A network topology refers to the layout of the computers and devices in a communications network An intranet is an internal network that uses Internet technologies An extranet allows customers or suppliers to access part of its 41  intranet Communications Software Communications software consists of programs that: Help users establish a connection to another computer or network Manage the transmission of data, instructions, and information Provide an interface for users to communicate with one another Communications Over the Telephone Network The public switched telephone network (PSTN) is the worldwide telephone system Dial-up lines 42 Dedicated line ISDN line DSL FTTP T-carrier line ATM 43 Communication devices A communications device is any type of hardware capable of transmitting data, instructions, and information between a sending device and a receiving device. A digital modem sends and receives data and information to and from a digital line Digital modems: Broadband modem (digital modem) is a communications device that sends and receives data and information to an from a digital line. Wireless modems: Some mobile users have a wireless modem that uses a mobile service provider s network to connect to the Internet wirelessly from a computer or mobile device. A network card enables a computer or device to access a network ’ Available in a variety of styles Wireless network cards often have an antenna Wireless access points: A wireless access point (WAP) is a central communications device that allows computers and devices to transfer data wirelessly among themselves, such as Wi–Fi. 44 Routers: A router is a communications device that connects multiple computers or other routers together and transmits data to its correct destination on a network. Hubs and Switches: A hub or switch is a device that provides a central point for cables in a network. Home Networks Home networks provide computers with the following capabilities: Connect to the Internet at the same time Share a single high-speed Internet connection Access files and programs on other computers Share peripherals Play multiplayer games Connect game consoles to the Internet Subscribe to and use VoIP 45 Types of wired home networks: Ethernet Powerline cable Phoneline Wireless Transmission Media Cellular radio is a form of broadcast radio that is used widely for mobile communications (Rooftop building satellite) Microwaves are radio waves that provide a high-speed signal transmission (Tall pole satellite) A communications satellite is a space station that receives microwave signals from an earth-based station, amplifies it, and broadcasts the signal over a wide area (Outside earth satellite) Chapter 10: COMPUTER SECURITY Digital Security Risks A digital security risk is any event or action that could cause a loss of or damage to a computer or mobile device hardware, software, data, information, or processing capability Any illegal act involving the use of a computer or related devices generally is referred to as a computer crime A cybercrime is an online or Internet-based illegal act 46  Hacker Cracker Script kiddie Corporate spies Unethical employees Cyberextortionist Cyberterrorist Hacker: Someone who accesses a computer or network illegally. Cracker: Someone who accesses a computer or network illegally, but has the intent of destroying data, stealing information, or other malicious action. Script kiddie: Someone has the same intent as a cracker but does not have the technical skills and knowledge. Corporate spies: Someone have excellent computer and networking skills and are hired to break into a specific computer and steal its proprietary data and information. 47 Unethical employees: Someone who break into their employers computers for a variety of reasons. Cyberextortionist: ’ Someone who demands payment to stop an attack on an organization s technology infrastructure. Cyberterrorist: Someone who uses the Internet or network to destroy or damage ’ computers for political reasons. Internet and Network Attacks Information transmitted over networks has a higher degree of security risk than information kept on an organization s premises 48 ’  Malware, short for malicious software, consists of programs that act without a user s knowledge and deliberately alter the operations of computers and mobile devices Common types of Malware ’ Virus – A potentially damaging program that affects, or infects a computer or mobile device negatively by altering the way the computer or device works without the user s knowledge or permission – May alter the way the computer works Worm ’ – A program that copies itself repeatedly, for example in memory or on a network, using up resources and possibly shutting down the computer, device, or network. Trojan horse – A program that hides within or looks like a legitimate program. A Trojan horse does not replicate itself to other computer or device Rootkit – A program that hides in a computer or mobile device and allows someone from a remote location to take full control of the computer or device. Spyware 49 – A program placed on a computer or mobile device without the user s knowledge that secretly collects information about the user and then communicates the information it collects to some outside source while the user is online ’ Adware – A program that displays an online advertisement in a banner, pop – up window, or pop – under window on webpages, email messages, or other Internet services Internet and Network Attacks An infected computer has one or more of the following symptoms: Operating system runs much slower than usual Available memory is less than expected 50  Files become corrupted Screen displays unusual message or image Music or unusual sound play randomly Existing programs and files disappear Programs or files do not work properly Unknown programs or files mysteriously appear System properties change Operating system does not start up Operating system shuts down unexpectedly Firewall A firewall is hardware and/or software that protects a network s resources from intrusion Unauthorized Access and Use ’ 51  Unauthorized access is the use of a computer or network without permission Unauthorized use is the use of a computer or its data for unapproved or possibly illegal activities Organizations take several measures to help prevent unauthorized access and use – Acceptable use policy – Disable file and printer sharing – Firewalls – Intrusion detection software Access controls define who can access a computer, when they can access it, and what actions they can take – Two-phase processes called identification and authentication – User name – Password – Passphrase – CAPTCHA A passphrase is a private combination of words, often containing mixed capitalization and punctuation, associated with a user name that allows access to certain computer resources A PIN (personal identification number), sometimes called a passcode, is a numeric password, either assignedby a company or selected by a user A possessed object is any item that you must carry to gain access 52  to a computer or computer facility – Often are used in combination with a personal identification number (PIN) A biometric device authenticates a person s identity by translating a personal characteristic into a digital code that is compared with a digital code in a computer or mobile device verifying a physical or behavioral characteristic ’ Digital forensics is the discovery, collection, and analysis of evidence found on computers and networks Many areas use digital forensics 1. Law enforcement 2. Criminal prosecutors 3. Military intelligence 53 4. Insurance agencies 5. Information security departments Hardware Theft and Vandalism Hardware theft is the act of stealing computer equipment Hardware vandalismis the act of defacing or destroying computer equipment To help reduce the of chances of theft, companies and schools use a variety of security measures 1. Physical access controls 2. Alarm systems 3. Cables to lock equipment2 4. Real time location system 5. Passwords, possessed objects, and biometrics Software Theft Software theft occurs when someone: 1. Steals software media 2. Intentionally erases programs 3. Illegally registers and/or activates a program 4. Illegally copies a program A single-user license agreement typically contains the following conditions:- 54 Permitted to: Install the software on one computer Make one copy of the software Remove the software from your computer before giving it away or selling it Not permitted to: Install the software on a network Give copies to friends or colleagues while continuing to use the software Export the software Rent or lease the software Copying, loaning, borrowing, renting, or distributing software can be a violation of copyright law During the product activation, which is conducted either online or by phone, users provide the software product s identification number to associate the software with the computer or mobile device on which the software is installed3 A license agreement is the right to use software ’ Information Theft Information theft occurs when someone steals personal or confidential information Encryption is a process of converting data that is readable by humans into encoded characters to prevent unauthorized access 55 What is a digital signature? A digital signature is an encrypted code that a person, website, or organization attaches to an electronic message to verify the identity of the message sender -Often used to ensure that an impostor is not participating in an Internet transaction Web browsers and Web sites use encryption techniques Popular security techniques include 1. Digital 2. Certificates 3. Transport Layer 4. Security (TLS) 5. Secure HTTP 6. VPN System Failure A system failure is the prolonged malfunction of a computer A variety of factors can lead to system failure, including: -Aging hardware -Natural disasters -Electrical power problems4 >>Noise, undervoltages, and overvoltages – Errors in computer programs How to protect from system failures? 56  Two ways to protect from system failures caused by electrical power variations include surge protectors and uninterruptable power supplies (UPS) Backing Up – The Ultimate Safeguard A backup is a duplicate of a file, program, or media that can be used if the original is lost, damaged, or destroyed -To back up a file means to make a copy of it Off-site backups are stored in a location separate from the computer or mobile device site Two categories of backups: -Full backup -Selective backup Ethics and Society Computer ethics are the moral guidelines that govern the use of computers and information systems Information accuracy is a concern – Not all information on the Web is correct Intellectual property rights are the rights to which creators are entitled for their work -A copyright protects any tangible form of expression5 ## An IT code of conduct is a written guideline that helps determine 57  whether a specific computer action is ethical or unethical or allowed/not allowed Information Privacy Information privacy refers to the right of individuals and companies to deny or restrict the collection, use, and dissemination of information about them Phishing is a scam in which a perpetrator sends an official looking email message that attempts to obtain your personal and/or financial information Pharming is a scam where a perpetrator attempts to obtain your personal and financial information via spoofing What is a cookie? A cookie is a small text file that a Web server stores on your computer Web sites use cookies for a variety of reasons: Allow for personalization Store users passwords Assist with online shopping Track how often users visit a site Target advertisements ’ Spam is an unsolicited e-mail message or newsgroup posting E-mail filtering blocks e-mail messages from designated sources Anti-spam programs attempt to remove spam before it reaches 58 your inbox Social engineering is defined as gaining unauthorized access or obtaining confidential Information by taking advantage of trust and naivety Employee monitoring involves the use of computers to observe, record, and review an employee s use of a computer ’ 59