Computer - a machine that can be programmed to automatically carry out sequences of arithmetic or logical operations (computation). Technically a computer doesn’t need to be electronic, nor even have a processor, RAM or hard disk. Processor - an electrical component that performs operations on an external data source. Co-processors - such as graphic processing units (GPUs). Some other coprocessors are physics processing units (PPUs) which are used to make physics related calculations mainly in video games, digital signal processors (DSPs) like IPUs or ISPs (image processors). Process - the instance of a computer program that is being executed by one or many threads.  Central Processing Unit (CPU) - The main processor in a system. RAM - Random-access memory. Multitasking - the concurrent execution of multiple tasks (processes) over a certain amount of time. Internet - a global system of interconnected computer networks that uses internet protocol suite (TCP/IP) Intranet - a private network (as opposed to the public networks of the internet) used for sharing information, easier communication, operating systems, and other computing services within an organization usually with the exclusion of outsiders. Extranet - a controlled private network that allows access to partners, vendors, suppliers, or an authorized set of customers, normally to a subset of the information accessible from the organization's intranet. Virtual Private Network (VPN) - a network architecture for virtually extending a private network across one or more other networks that are untrusted (not controlled by the entity aiming to implement the VPN) or need to be isolated. The goal of a VPN is to allow network hosts like PCs and servers to exchange network messages across another network to access private content, as if they were part of the same network. Ethernet - a family of wired computer networking technologies commonly used in local, metropolitan and wide area networks.  Scale Of Computer Networks Nanoscale - a set of interconnected nanomachines that perform only simple tasks like computing, data storing, sensing and articulation. Near-field (NFC) - a set of communication protocols that enable communication between two electronic devices over a distance of 1.6 inches or less. The Secure Element chip, an NFC chip that contains data such as the Secure Element identifier (SEID) for secure transactions. This chip is commonly found in smartphones and other NFC devices. Body - a wireless network of wearable computing devices, BAN devices may also be embedded inside the body as implants or pills. Personal - a computer network for interconnecting electronic devices within a person’s individual workspace. PANs provide data transmission among devices like computers, smartphones, tablets and personal digital assistants. A wireless personal area network deals with things like IrDA, Bluetooth, NearLink ro Zigbee. Universal Serial Bus (USB) - Near-me - a grouping of communication devices that are in close physical proximity to each other but not necessarily connected to the same communication network infrastructure. Local (LAN) - a computer network that interconnects computers with a limited area like a residence, school, laboratory, university campus or office building. Storage (SAN) Wireless (WLAN) - a wireless computer network that links two or more devices using wireless communication to form a LAN within a limited area like a home, school, campus or office building. Virtual (VLAN) HOME (HAN) Building Campus (CAN) - a campus area network or corporate area network is a computer network made up of an interconnection of local area networks within a limited geographical area. The networking equipment, such as switches, routers, and the transmission media, like optical fibers, copper plant, Cat5 Cabling is owned almost entirely by the campus, enterprise, university, etc. A CAN is larger than a LAN but smaller than a MAN or WAN. Some examples of CANs are Stanford University Network, Project Athena, Andrew Project, and the networks at Googleplex. The range of CANs are 1 - 5 km or 0.6 miles to 3.1 miles. Backbone - a part of a computer network that interconnects networks providing a path for the exchange of information between different LANs or subnetworks. Usually the backbone’s capacity is more than the networks connected to it. Metropolitan (MAN) - a computer network that interconnects users with computer resources in a geographical region the size of a metropolitan area. The interconnection of LANs in a city into a single larger network that may also offer efficient connection to a WAN. Municipal Wireless (MWN) - a citywide wireless network Wide (WAN) - A wide area network covers a large geographical distance but also usually involves leased telecommunication circuits. Cloud - Internet area network (IAN) Internet PROGRAMMING LANGUAGES Code - an algorithm that uniquely represents symbols from some source alphabet, by encoded strings, which may in some other target alphabet. Operating system - a system software that manages computer hardware and software resources, and provides common services for computer programs. Linux’s predecessors were: Unix (1970s) (developed by AT&T Bell Labs) Posix (the standardization of Unix) (Portable Operating System Interface) - made to insure other systems would be compatible with each other. Minix (was made for academic use) Linux (1991) (made by Linus Torvalds) - free to distribute, modify and sell to others. Referring to the operating system kernel. Mac OS, Android, Free BSD and Linux are all mostly Posix compliant. Linux distros Closed source - the source code isn’t available to the public, it’s only accessible to the organization that developed it or those who pay access to it. Some closed source softwares include Microsoft Windows, Adobe Photoshop, Apple IOS and Microsoft Office. Open source - the source code is available for the public, so anyone can read or modify it. Open source software is often free. Some open source softwares are Linux, WordPress, Mozilla Firefox, Apache, and Android. Operating systems segregated by country: OpenKylin (China) BharOS (India) Astra Linux (Russia) Canaima (China (Inspur)) Nova (Cuba) Red Star OS (N. Korea) List of Operating Systems LANGUAGES (Programming / Markup / Style Sheet) Basic (Dartmouth, 1964) Scratch JavaScript Python Specialized dynamic high-level languages: Bash Powershell HTML CSS SQL Lua (Brazil, easier and faster than Python. Embedded into engines like Roblox and WOW) Ruby (Japan, object-oriented language) Julia (2009, MIT) used for scientific computing Static high-level languages: Java (runs on a JVM, syntactic dumpster fire) C Sharp (used for Unity games) Typescript (2012, USA, Kotlin (2016, Czechia, Android) Swift (2012, USA, IOS) Dart (Flutter framework) Go (developed by Google to build low-level systems, designed as a replacement for C, 2009 USA) Functional languages: Haskell (1990, global, inspired by the Miranda language, named after the mathematician) F sharp (also imperative and object-oriented) Scala Clojure (functional and dynamic) Ocaml (1995, France, used extensively with Facebook) Elixir (ruby-like syntax) Elm (purely functional language, 2002 Harvard, complies to JavaScript) Low-level systems languages: C C++ Rust Modern languages: V (2019, Netherlands, high-performance systems language similar to Go and doesn’t use garage collector or like Rust doesn’t use borrow checking) Zig (2016, USA, simplifies low-level programming) Nim (2008, Germany) Carbon (supposed to be a successor to C++, 2025) Solidity (2018, global) Hack Historically important languages: Fortran (1957) LISP (1958) ALGOL (1958) Cobol (1959, over 40% of banking systems still use it, and 2 billion lines of code still in production today) APL (A programming language) Pascal Simula Erlang (1986, Sweden, basically powered the entire telecom industry) Ada (1977, USA, general purpose language) Prolog ML (Meta language) Esoteric languages: INTERCAL (1972, USA) Brainfuck (1993, Switzerland) Malbolge (1998) Chef (2002) Shakespeare (2001) PIET LOL code (2007) Emojicode (2016) Holy C Lowest level: Assembly (1947) Machine Codes / Raw Binary Transistors (1947, on a CPU) Quantum Electrodynamics (1927)