CLASSIFICATION OF COMPUTERS
Computers are classified according to their data processing speed, amount of data that they can hold and process. Depending upon their speed and memory size, computers are classified into following four main groups.
These computers are also called personal computers. Two major types of these computers are laptop or desktop computers. Only one user uses these computers at a time that’s why they are also known as personal computers. The personal computer is mostly preferred as home computers, and almost all users are familiar with them. The memory size and working capabilities of these computers are quite low in comparison to other classes of computers.
These computers use a microprocessor chip and this chip is used instead of a CPU which means that this microprocessor chip works as a CPU. There are various types of computers as discussed below:
(A) desktop computer
is a personal computer (PC) in a form intended for regular use at a single location. These are generally kept on a table top to work upon. These are the most common types of micro computers. Two popular series of personal computers are the IBM PC and the Apple Macintosh. DLL
(B) Notebook Computer
A notebook computer is also called a laptop. A notebook computer has the processor, memory, keyboard, computer hard drive and the display integrated into a single unit that can operate on battery. A notebook is a small, lightweight computer that you can easily transport from one place to another. Users with mobile computing needs, such as business travellers, often use a laptop.
(c) Tablet PC
A tablet PC is a wireless, portable personal computer with a touch screen interface. The tablet form factor is typically smaller than a notebook computer but larger than a smart phone. The tablet PC relies on digital ink technology, where a digitizer is laid under or over an LCD screen to create an electromagnetic field that can capture the movement of the special purpose pen and record the movement on the LCD screen. The effect is like writing on paper with liquid ink.
(d) Personal Digital Assistant (PDA)
PDAS are handheld devices that were originally designed as personal organizers, but became much more versatile over the years. PDAS have many uses: calculating, use as a clock and calendar, playing computer games, accessing the internet, sending and receiving e-mail, and use as a video recorder, recording notes, use as an address book and use as a spreadsheet. Newer PDAS also have both colour screens and audio capabilities, enabling them to be used as mobile phones, web browsers or portable media players. One of the most significant PDA characteristic is the presence of a touch screen.
Minicomputers are computers that are somewhere in between a microcomputer and a mainframe computer. A minicomputer is a multi-user system. They are used to control machines in a manufacturing unit. They have higher memory, higher processing power and higher storage as compared to micro computers.
Mainframe computers can process several million-program instructions per second. Large organizations rely on these room-size systems to handle large programs with lots of data. Mainframes are mainly used by insurance companies, banks, airline and railway reservation systems, etc.
Super computers are the fastest calculating devices ever invented. The largest in size, the most expensive than any other is assessed and known as super computer. It processes trillions of instructions in seconds. These machines are for applications requiring very large programs and huge amounts of data that must be processed quickly. Governments specially use a super computer for their totally different calculations and significant jobs. Moreover, different industries use this huge computer for designing their products. In most of the Hollywood’s movies it’s used for animation purposes. This type of computer is additionally useful for forecasting weather reports worldwide.