Introduction to Computers - Lec 1 & 2 PDF

 A World of information Computers are everywhere: at work, at school, and at home. Mobile computers and mobile devices are small enough to carry. Mobile devices, such as many cell phones, often are classified as computers. Mobile devices are Computers?!!! Computers are a primary m...

 A World of information Computers are everywhere: at work, at school, and at home. Mobile computers and mobile devices are small enough to carry. Mobile devices, such as many cell phones, often are classified as computers. Mobile devices are Computers?!!! Computers are a primary means of local and global communication for billions of people. Through computers, society has instant access to information from around the globe. A World of information Banks place ATMs (automated teller machines) (embedded computer) all over the world, so that customers can deposit and withdraw funds anywhere at anytime. Vehicles include onboard navigation systems (embedded computer) that provide directions, call for emergency services, and track the vehicle if it is stolen. People also spend hours of leisure time using a computer. They play games, listen to music or radio broadcasts, ……….. What Is a Computer? A computer is an electronic device, operating under the control of instructions stored in its own memory. A computer can: accept data, process the data according to specified rules, produce results, and store the results for future use Data and Information Computers process data into information. What is Data?! Data is a collection of unprocessed items, which can include text, numbers, images, audio, and video. Information conveys meaning and is useful to people. Computers process several data items to print information in the form of a cash register receipt. Information Processing Cycle Computers process data (input) into information (output). Computers carry out processes using instructions, instructions are the steps that tell the computer how to perform a particular task. A collection of related instructions organized for a common purpose is referred to as software. The series of input, process, output, and storage activities as the information processing cycle.  Most computers today communicate with other computers. As a result, communications also has become an essential element of the information processing cycle. The Components of a Computer A computer contains many electric, electronic, and mechanical components known as hardware. These components include: input devices, output devices, a system unit, storage devices, and communications devices. Input Devices An input device is any hardware component that allows you to enter data and instructions into a computer. Five widely used input devices are the keyboard, mouse, microphone, scanner, and Web cam. What is the job of each previous mentioned device?!!!! Output Devices An output device is any hardware component that conveys information to one or more people. Three commonly used output devices are: a printer, a monitor, and speakers System Unit The system unit is a case that contains the electronic components of the computer that are used to process data. The circuitry of the system unit usually is part of or is connected to a circuit board called the motherboard Two main components on the motherboard are: processor and memory.  The processor, also called a CPU (central processing unit), is the electronic component that interprets and carries out the basic instructions that operate the computer. Memory consists of electronic components that store instructions waiting to be executed and data needed by those instructions. The computer memory is volatile, which means its contents are erased when the computer is shut off. Storage Devices Storage holds data, instructions, and information for future use. For example, computers can store hundreds or millions of customer names and addresses. Storage holds these items permanently. Examples of storage media are USB flash drives, hard disks, optical discs, and memory cards. A storage device records (writes) and/or retrieves (reads) items to and from storage media.  A USB flash drive is a portable storage device that is small and lightweight enough to be transported on a keychain or in a pocket. A hard disk provides much greater storage capacity than a USB flash drive. Hard disks are enclosed in an airtight, sealed case. Although some are portable, most are housed inside the system unit Portable hard disks are either external or removable. Communications Devices A communications device is a hardware component that enables a computer to: send (transmit) and receive data, instructions, and information to and from: one or more computers or mobile devices. A widely used communications device is a modem.  Communications occur over cables, telephone lines, cellular radio networks, satellites, and other transmission media. Some transmission media, such as satellites and cellular radio networks, are wireless, which means they have no physical lines or wires. Computer Characteristics Speed: When data, instructions, and information flow along electronic circuits in a computer, they travel at incredibly fast speeds. Reliability: The electronic components in modern computers are dependable and reliable because they rarely break or fail. Consistency: Given the same input and processes, a computer will produce the same results — consistently. Storage: A computer can transfer data quickly from storage to memory, process it, and then store it again for future use.  Communications: Most computers today can communicate with other computers, often wirelessly. Computers with this capability can share any of the four information processing cycle operations — input, process, output, and storage — with another computer or a user. Computers Misuse Health Risks: Prolonged or improper computer use can lead to injuries or disorders of the hands, wrists, elbows, eyes, neck, and back. Computer users can protect themselves from these health risks through proper workplace design, good posture while at the computer, and appropriately spaced work breaks. Two behavioral health risks are computer addiction and technology overload.  Violation of Privacy: Nearly every life event is stored in a computer somewhere... in medical records, credit reports,… Individuals could have find their privacy violated and identities stolen Public Safety: Adults, teens, and children around the world are using computers to share publicly their photos, videos, journals, music, and other personal information. Do not share information that would allow others to identify or locate you and do not disclose identification numbers, passwords. Networks and the Internet A network is a collection of computers and devices connected together, often wirelessly, via communications devices and transmission media. Networks allow computers to share resources, such as hardware, software, data, and information. Sharing resources saves time and money. The server controls access to the resources on a network. The other computers on the network, each called a client or workstation, request resources from the server  What major differences between the server and client computers? Home networks usually are small, existing within a single structure. Business and school networks can be small, such as in a room or building, or widespread, connecting computers and devices across a city, country, or the globe. The world’s largest computer network is the Internet! The Internet The Internet is a worldwide collection of networks that connects millions of businesses, government agencies, educational institutions, and individuals.  People around the world use the Internet daily for a variety of reasons: Communicate with and meet other people Conduct research and access a wealth of information and news Shop for goods and services Bank and invest Participate in online training Engage in entertaining activities, such as planning vacations, playing online games, listening to music, watching or editing videos.  Download music and videos Share information, photos, and videos Access and interact with Web applications With instant messaging, you can have a live conversation with another connected user. In a chat room, you can communicate with multiple users at the same time — much like a group discussion. You also can use the Internet to make a telephone call  The Web, short for World Wide Web, is one of the more popular services on the Internet. The Web contains billions of documents called Web pages. Web pages often have built-in connections, or links, to other documents, graphics, other Web pages, or Web sites. A Web site is a collection of related Web pages. A blog is an informal Web site consisting of timestamped articles in a diary or journal format, usually listed in reverse chronological order.  A Web application is a Web site that allows users to access and interact with software from any computer or device that is connected to the Internet. Ex: Web applications include those that allow you to send and receive e-mail messages, prepare your taxes, organize digital photos, create documents, and play games. Thank you!