Part 1 computer and information technology system
A computer is a machine that manipulates data according to a list of instructions. The first devices that resemble modern computers date to the mid-20th century (1940–1945), although the computer concept and various machines similar to computers existed earlier. Early electronic computers were the size of a large room, consuming as much power as several hundred modern personal computers (PC). Modern computers are based on tiny integrated circuits and are millions to billions of times more capable while occupying a fraction of the space. Today, simple computers may be made small enough to fit into a wristwatch and be powered from a watch battery. Personal computers, in various forms, are icons of the Information Age and are what most people think of as "a computer"; however, the most common form of computer in use today is the embedded computer. Embedded computers are small, simple devices that are used to control other devices for example, they may be found in machines ranging from fighter aircraft to industrial robots, digital cameras, and children's toys.
Network computer devices that originate, route and terminate the data are called network nodes. Nodes can include hosts such as personal computers, phones, servers as well as networking hardware.
A computer network is a telecommunications network which allows computers to exchange data. In computer networks, networked computing devices exchange data with each other using a data link. The connections between nodes are established using either cable media or wireless media. The best-known computer network is the Internet.
Computer networks support an enormous number of applications and services such as access to the World Wide Web, digital video, digital audio, shared use of application and storage servers, printers, and fax machines, and use of email and instant messaging applications as well as many others. In most cases, application-specific communications protocols are layered over other more general communications protocols.
Information technology (IT) is the application of computers and internet to store, retrieve, transmit, and manipulate data, or an information often in the context of a business or other enterprise. IT is considered a subset of information and communications technology (ICT). In 2012, Zuppo proposed an ICT hierarchy where each hierarchy level "contain some degree of commonality in that they are related to technologies that facilitate the transfer of information and various types of electronically mediated communications." Business/IT was one level of the ICT hierarchy.
Information and communications technology (ICT) is an extended term for information technology (IT) which stresses the role of unified communications and the integration of telecommunications , computers as well as necessary enterprise software, middleware, storage, and audio-visual systems, which enable users to access, store, transmit, and manipulate information.