IT Infrastructure Administration

• An administrator is in charge of some portion of the IT infrastructure.
• Network administrators oversee all aspects of the computer network, including laying cable, making connections, and working with network hardware.
• Database administrators focus on the design, development, and support of database management systems (DBMSs).
• Security administrators install, configure, and administer firewall security to protect organizational systems.
• Web administrators maintain web storage, which includes installing, configuring, maintaining, securing, and troubleshooting the web server.
• IT is gathering data, processing it into information, and disseminating it using technology, supported by IT personnel.
• Information Technology describes the technology infrastructure, including hardware, software, networks, and databases, that supports information systems.
• Computers perform four operations, Input, Processing, Output and Storage
• The CPU executes program instructions and commands computer components.
• Memory stores the program being executed and the data for each program.
• The I/O subsystem includes peripheral devices for input, output, storage, and networking.
• The bus allows information to move between components.
• The system unit is a key feature of computers, containing components that enable the system to run.
• Dynamic RAM (DRAM) is main memory.
• Static RAM (SRAM) is cache memory and registers.
• ROM retains its contents indefinitely.
• BIOS is the Basic Input Output System.
• A hard drive stores data even when the computer is turned off.
• Peripheral devices are located outside the system unit but connected physically or wirelessly.
• Hardware is the physical components of the computer
• Software consists of programs and other operating information used by the computer
• A network is a collection of computers and resources connected to communicate with each other
• Users are the people who use the computer system
• First-generation machines used vacuum tubes.
• Second-generation machines used transistors.
• Third-generation machines used integrated circuits.
• Fourth-generation machines used microprocessors.
• Machine language is the lowest-level programming language, using binary.
• Assembly language uses specified instructions using words.
• High-level languages enable programmers to write programs independent of computer type.
• Compilers require all software components to be defined before compilation.
• Interpreted languages run inside an interpreter, which converts and executes commands line by line.
• C++, uses a vocabulary and rules to instruct a computer.
• Python: used as an easy language that does not require a compiler for debugging.
• JavaScript is designed for user engagement on web pages.
• Tcl: prototyping is done to allow creation of GUIs, Tcl is a simple and compact language but is also very powerful.
• PHP: an all-purpose language is especially suitable for web development.
• A computer network is a collection of computers and resources connected for communication.
• Bandwidth is the transfer rate over a medium, measured in bits per second (bps).
• A network hub connects multiple computers.
• A network switch sends transmissions to a specific computer.
• A router connects multiple networks together
• A wireless access point connects to a hub, switch, or router and sends a wireless signal.
• Radio waves provide access to networks over long distances.
• An IP address is a series of numbers indicating a specific internet location.
• A server is a computer that takes requests and responds with information.

Network Types

• In a Bus network, devices connect along a single cable.
• In Mesh networks, every device connects directly to every other device.
• In Ring networks, each device connects directly to its neighbors, and messages are forwarded until they reach their destination.
• Star networks centralize connections through a single machine.
• Confidentiality ensures data is secure and not accessible to unauthorized users.
• Integrity ensures data is correct.
• Availability ensures information is available when and where needed.
• Strategic risk analysis translates security policies into mechanisms supporting information security.
• Social engineering is a threat that targets users.
• Phishing targets individuals via email, posing as a reputable entity to steal personal information.
• Hacking is when someone gains unauthorized access to a host system.
• Malware is 'malicious' software.
• Spyware is often unknowingly downloaded when accessing web storage.
• Denial of service (DOS) attacks flood a server with messages, preventing legitimate access.
• Firewalls prevent certain messages from entering or leaving a network, and antivirus software seeks out malware.
• Antivirus software identifies if a file contains a virus or form of malware.
• Information security ensures the confidentiality, integrity, and availability of information during storage, processing, and transmission.
• Encryption obfuscates information on a computer or network, making it unreadable if intercepted.
• Symmetric key encryption uses the same key for encryption and decryption.
• Public-key encryption uses a public and private key.
• Software includes systems and programs developed for business functions.
• Application software are programs that end users run to accomplish tasks
• Operating system (OS) programs designed to improve software and hardware access.
• Server software works with hardware to provide a network service.
• Cloud computing combines distributed computing, computer networks, and storage area networks to offload computation and storage to the cloud.
• The kernel is the core component of the OS.
• Device drivers provide interfaces between the OS and hardware.
• A shell is a user interface, often personalized.
• System utilities let users monitor and improve system performance.
• GUI allows users to control the computer with a mouse.
• Web servers respond to HTTP requests.
• Proxy servers act as a giant cache of web pages within an organization.
• Database servers allow database access across a network.
• Proprietary software is purchased from a vendor.
• Shareware provides a trial version of software.
• Freeware is obsolete software or software with no support.
• Public Domain software has been moved into the public domain.
• The algorithm is a formula or procedure for solving a problem.
• The Flat file database is used to for data that is fairly minimal
• A relational database has multiple tables (relations) with interrelated fields.
• Hierarchical databases organize data in a tree-like structure.
• Business Intelligence (BI) is knowledge derived from information.
• A Business Intelligence system capture’s knowledge within information systems for strategic decisions.
• SQL interacts with data in databases with commands like SELECT fields FROM tables WHERE fields match criteria.
• Quality data is relevant, timely, thorough, accurate, and reliable.
• The IT department supports the day-to-day technology needs of an organization in order to reach goals.
• Business continuity encompasses IT systems and processes, with key components being a plan and its testing.
• A hot storage is a physical location fully equipped for operations, allowing the quickest return to business.
• A cold storage is a physical location without equipment, requiring the organization to purchase and install hardware and software.
• Bluetooth enables devices to exchange data wirelessly.
• The Internet of Things refers to devices connected to the Internet.
• Big data integrates vast amounts of data to find relationships.
• SaaS allows businesses to access and use software over the Internet.
• PaaS is a tool to develop and deliver applications more reliably.
• IaaS has all resources located outside of the organization and accessible everywhere.
• Ethics is a code of moral conduct.

The 10 Commandments of Computer Ethics

• Do not use a computer to hard other people
• Users shall never interfere with other people's files
• Do not copy files or use them to steal
• Users shalt not copy proprietary software
• Users shall think about the social consequences of the program