Computers can be classified, or typed, in many ways. Some general classifications of digital computers are summarized below. For others, see Category: Computer classes.
Video Classes of computers
Class by size
Microcomputers (personal computer)
Microcomputers became the most common type of computer in the late 20th century. The term "microcomputer" is introduced with the emergence of systems based on single-chip microprocessors. The most famous early system was the Altair 8800, which was introduced in 1975. The term "microcomputer" is practically an anachronism.
These computers include:
- Desktop computer - A case is placed under or over the table. The display may be optional, depending on usage. The size of the case may vary depending on the expansion slot required. Very small computers like these can be integrated into the monitor.
- Computer rackmount - These computer cases fit into the 19-inch rack, and can be optimized space and very flat. Special displays, keyboard and mouse may not be present, but a KVM switch or internal remote control (via LAN or other means) can be used to gain console access.
- In-car computers (carputer) - Built into cars, for entertainment, navigation, etc.
- Game console - Fixed computers tailor-made for entertainment purposes such as (video games).
Smaller microcomputers are also called mobile devices:
- Laptops and notebook computers - Portable and all in one case.
- Tablet computers - Just like laptops, but with touch screens, completely replace the physical keyboard.
- Smartphones, smartbooks, PDAs, and palmtop computers - Small handheld computers with limited hardware.
- Programmable Calculator - Like a small handheld, but specialized in math jobs.
- Handheld game console - Same as game console, but small and portable.
Minicomputer (midrange computer)
Minicomputer is a multi-user computer class located in the middle range of the computing spectrum, among the smallest mainframe computers and the largest single-user system (microcomputer or personal computer). The terms superminicomputer or supermini are used to distinguish stronger minikomputers that approach the mainframe in capability. Superminis (such as DEC VAX or Data General Eclipse MV/8000) are usually 32-bit when most mini-computers (such as PDP-11 or Data General Eclipse or IBM Series/1) are 16-bit. This traditional minicomputer in the last few decades of the 20th century, found in small to medium-sized businesses, laboratories and embedded in (for example) hospital CAT scanners, will often be mounted on shelves and connected to one or more terminals or ribbons/mainframe and unlike most personal computers, but requires less space and electrical power than regular mainframes. The contemporary term for minicomputers is midrange computers, such as SPARC, POWER and Itanium-based systems higher than Oracle Corporation, IBM and Hewlett-Packard, and their size is now usually smaller, as is the case of towers.
Mainframe computer
The term computer termframe was created to distinguish a large, traditional, institutional computer meant to serve multiple users from a smaller, single user machine. These computers are able to handle and process large amounts of data quickly. Mainframe computers are used in large institutions such as governments, banks and large corporations. They are measured in MIPS (million instructions per second) and can respond to hundreds of millions of users at once.
Supercomputer
A Supercomputer is focused on performing tasks involving intense numerical calculations such as weather forecasts, fluid dynamics, nuclear simulations, theoretical astrophysics, and complex scientific calculations. Supercomputers are computers that are at the forefront of current processing capacity, especially speed calculations. The term supercomputer itself is rather fluid, and the speed of today's supercomputers tends to be typical of future computers. The processing speed of a supercomputer is measured in floating point operations per second, or FLOPS. An example of a floating point operation is the calculation of a mathematical equation in a real number. In terms of computational capabilities, memory size and speed, I/O technology, and topology issues such as bandwidth and latency, supercomputers are the most powerful, costly, and ineffective in terms of cost just for batch or transaction processing. Transaction processing is handled by less powerful computers such as server computers or mainframes. They are mainly stored in a cool environment for proper functioning.
Maps Classes of computers
Class by function
Server
Servers usually refer to a dedicated computer to provide one or more services. For example, a computer dedicated to a database can be called a "database server". "File server" manages a large collection of computer files. "Web server" processes web pages and web applications. Many smaller servers are actually personal computers that have been dedicated to providing services to other computers. The server is expected to be reliable (eg RAM error correction, excessive cooling, standalone monitoring, RAID), suitable for walking for several years, and provide a useful diagnosis in case of errors. For increased security, the server may be mirrored
Terminal server
It provides GUI sessions that can be used by client PCs that work however like remote controls. Only the screen (and audio) is displayed on the client. The GUI application runs on the server, the data (as in the file) will be stored on the same LAN, thus avoiding problems, if the client PC is damaged or stolen.
Virtual machine
The server can run multiple virtual machines (VMs) for various events, providing the same environment for each VM as it runs on dedicated hardware. Different operating systems (OS) can run at the same time. This technology approach requires special hardware support to be useful and first of all mainframe domains and other large computers. Currently, most personal computers are equipped for this task, but for long-term or system-critical operations, special server hardware may be required.
Another approach is to apply the VM at the operating system level, so that all VMs run on the same OS instance (or incarnation), but are fundamentally separated to not interfere with each other.
Workstation
Workstations are computers intended to serve one user and may contain special hardware enhancements not found on personal computers. In the mid-1990s personal computers achieved the capability of processing mini-computers and workstations. Also, with the release of multi-tasking systems such as OS/2, Windows NT and Linux, personal computer operating systems can perform the task of this machine class.
Information device
Information devices are computers designed specifically to perform certain "user-friendly" functions - such as playing music, photography, or text editing. This term is most often applied to mobile devices, although there are also portable and desktop devices of this class.
Embedded computer
An embedded computer is a computer that is part of a machine or device. The embedded computer generally runs programs that are stored in non-volatile memory and are only intended to operate certain machines or devices. Embedded computers are very common. The majority are microcontrollers. Embedded computers are usually required to operate continuously without being reset or rebooted, and after being used in the job, the software usually can not be modified. The car may contain a number of embedded computers; However, a washing machine or DVD player will only contain one microcontroller. Embedded computers are selected to meet certain application requirements, and are much slower and cheaper than the CPUs found on personal computers.
Class based on usage
Public computer
The public computer is open for general use, probably as an Interactive kiosk. There are many places that can be used, such as cybercafes, schools and libraries.
They are usually walled in flames and restricted to only running their pre-installed software. The operating system is difficult to change and/or reside in the file server. For example, a "thin client" machine in an educational institution can be reset to the original state of the classroom. Public computers are not expected to store individual data files.
Personal computer
A personal computer has one user who may also be the owner (although the term also comes also means any computer hardware like the original IBM PC, regardless of how it is used). These users can often use all hardware resources, have full access to any part of the computer and have the right to install/uninstall the software. Personal computers typically store personal files, and often the owner/user is responsible for routine maintenance such as deleting unwanted files and virus scanning. Some computers in a business setting are for one user but also served by staff with protocols to ensure proper maintenance.
This is a computer where different people may enter at different times; unlike public computers, they will have long-term usernames and passwords, with the files they see and computer settings tailored to their specific accounts. Often important data files will be on the central file server, so someone can log in to a different computer but still see the same file. The computer (or workstation) may be a "thin client" or an X terminal, otherwise it may have its own disk for some or all of the system files, but usually needs to be networked across the system for full functionality. Such systems usually require system administrators to organize and maintain hardware and software.
Display computer
A computer used only to display selected material (usually audio-visual, or a simple slide show) in a shop, meeting or trade show. These computers may have more capabilities than those used for; they tend to have WiFi and are able to access the Internet, but rarely firewall (but have limited port access or are monitored in some way). Such computers are used and maintained as equipment, and are not usually used as primary storage for important files.
Classified by Computer Technology Generation
- First generation computers use a vacuum tube like a specially designed 6J6 or 6J6 tube - or even a mechanical, and relatively slow, energy hunger and the earliest computer is less flexible in its programmability.
- Second generation computers use discrete transistors, making them smaller and consuming less power.
- Third generation computers use Integrated Circuits, the main difference between hardware in computers of the 1960s and now becomes the density of transistors in each IC (starting with Small Scale Integration chip like SN7400 logic transistor-transistor gate (TTL) with 20 transistors , through Intermediate Scale Integration and Large-Scale Integration to a very large-scale Integration (VLSI) with over ten billion transistors in a single "chip" IC.
See also
- List of computer size categories
- Bell's classroom computer law
- Analog computer
References
External links
- Four types of Computers
Source of the article : Wikipedia
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