Lesson 3: Types of Computers

A quantum computer is any computing device that performs operations on data directly using quantum mechanical methods such as quantum entanglement. Data in a traditional computer is measured by bits; data in a quantum computer is measured by qubits. The core concept of quantum computation is that the quantum properties of particles can also be used to describe and structure data, and that quantum mechanisms can be used to perform operations on this data.

Experiments have already been conducted in which quantum computational procedures on a very limited number of qubits were performed. Many national military and government funding agencies support quantum computing research to establish quantum computers both for civilian in addition to national security purposes, such as cryptanalysis.

Large-scale quantum computers, it is widely assumed, will be capable of solving certain issues quickly than any classical computer. Quantum computers differ from traditional computers like DNA computers and transistor-based computers, even though these may eventually use some other kind of quantum mechanical effect. Some computing architectures, such as optical computers, use traditional superposition of electromagnetic radiation, but they lack the computational speed-up potential of quantum computers because they lack some specific quantum mechanical resources, such as entanglement.

A supercomputer is a computer with a large amount of memory and performance. This computer can perform tasks quicker than every computer among its generation. They are often thousands of times quicker than the standard personal computers (PCs) of the period. Because supercomputers can do mathematical tasks quickly, they are utilized for weather prediction, code-breaking, genetic research, and other tasks that need a large number of computations. As new computers of any type become more capable, they are built with capabilities formerly reserved for supercomputers. Emerging supercomputers continue to outperform them with cutting edge technology.

Supercomputers are created by electrical engineers by connecting thousands of microprocessors

Mainframes (sometimes known colloquially as "big iron") are enormous and expensive computers used primarily by government bodies and major corporations for mission essential applications such as censuses, manufacturing statistics, ERP, or financial transaction processing.

The phrase was coined in the early 1970s with the emergence of smaller, less complicated computers like the DEC PDP series,which were dubbed minicomputers. The name "mainframe" was later adopted by the industry and users to identify larger, earlier models.

The capabilities of modern mainframe computers are defined less by their performance capabilities and more by their extremely high-end design, durability, premium technical support, top-tier reliability, and rigorous support for older software. These machines can, and do, continue for decades without interruption, with maintenance taking place while they are running. Mainframe suppliers provide services such as off-site redundancy, which means that if a computer fails, the vendor may run clients' programs on their own machines (sometimes without users even noticing the difference) while the machine is being repaired.

Mainframes frequently accommodate thousands of concurrent users who get access using "dumb" interfaces or terminal emulation. Early mainframes offered either offered time-sharing mode or ran in batch mode, so clients had no immediate access to the computing service, instead relying on it to perform back office activities. Mainframes were so named at the time because of their massive size and need for specialised HVAC and electrical energy. Nowadays, mainframes can be accessed using any interface, such as the web. Blade servers, rather than mainframes, are increasingly in need of superior cooling systems.

A server is a network computer, computer software, or device that executes client requests in a client-server architecture. A web server, for example, on the World Wide Web, is a computer that utilizes the HTTP protocol to transfer web pages to a user's computer whenever the user request them. A print server maintains one or more printers on a local area network and prints files provided to by client computers. Servers also include network servers (which manage network activity) and file servers.

A minicomputer is a computer that’s smaller, cheaper, and far less capable than a mainframe and supercomputer, but more costly and capable than that of a personal computer. Minicomputers are utilized for scientific and technical computations, as well as commercial transaction processing, file management, and database administration. Minicomputers are capable of handling multiple simultaneously.

A personal computer is a small-scale computer intended to be used by a single person at a time. A personal computer, was once referred to as a microcomputer, is now more often referred to as a PC or a system relying on a single microprocessor. Laptops and desktop computers are examples of common microcomputers.

A workstation is a computer that is used to do scientific or technical computations or tasks. These are often pricey, high-end computers. They are not the same as regular computers in use for text processing. They frequently feature operating systems that let several people to operate upon that computer at the same time. Workstations are frequently linked toward a local area network (LAN), which then distributes all resources of one or more powerful workstation computers. They may be accessed via computer terminals. Almost all workstations nowadays run a Unix or Unix-like operating system.