Most commonly used computers are the microcomputers based on single chip microprocessor technology like the Personal Computer or PC commonly known as Desktop, Laptop and Palmtop computer. These three types are very prominently used nowadays by people of all fields and classes to meet their suitable requirements with laptops and palmtop computers being in vogue vis a vis desktops.
* PC or Desktop: Desktop computers are the most suitable type of computers for use in offices, schools and other work places in performing different operations like documentation, accounting and internet browsing, etc. It consists of a desktop display known as Monitor with a key board placed on table top and a case containing mother board with processing unit known as CPU normally placed under the table. Desktops are generally cheaper than laptops and palmtop computers.
* Laptop: Laptops are slim and light weighted as compared to desktops. They can be easily placed on the lap to work conveniently. Laptop mother boards have built in wireless technology. Therefore they can be easily carried and run on rechargeable battery. Unlike desktops, laptops do not require any extra space for storage.
* PalmTop: It is very small in size and can be placed on the palm. Palmtops make use of an electronic pen known as stylus in place of key board for operating. Data feeding is done through hand written messages using this pen. A palmtop is also known as PDA (Personal Digital Assistant). It is also known as hand held or pocket computer. But a palmtop can perform limited functions and is mostly used as a phone book, diary or note book and for sending and receiving mails and playing games.
Classification Based on Operations
Besides the above 3 basic classifications, there are other classifications according to principles of operation or according to size and performance. Based on principles of operation, there are following three types:
* Analog: Analog computer works on range of values which keep varying continuously and give approximate results of the computations. These computers are used for calculating temperature, pressure, voltage and speed.
* Digital: Digital computers operate on digital data using binary number system. Widely used in engineering and technology fields, they are more accurate and give faster results.
* Hybrid: Hybrid computers operate on a combined version of analog and digital features. These computers are mostly used for specialized tasks like automatic operations of machines and monitoring of complicated physical processes.
Based on their size, capacity and performance computers can be classified into super computers, mainframe computers, minicomputers and microcomputers.
* Super Computer: A large computer in terms of processing capacity, it can process hundreds of millions of instructions at a single moment. It is highly expensive and is useful for nuclear technology, scientific research, geological surveys and weather reports.
* Mainframe: Mainframe computer is a computer with a large CPU for processing all operations linked with many hundreds of other computers in its frame work. They are also capable of efficiently monitoring hundreds of millions of transactions concurrently. They are widely used in banks, railways and airlines.
* Mini Computer: A minicomputer is smaller than mainframe computer in operations and less expensive. But it can support more than 100 users at a single time.
* Micro Computer: A microcomputer is based on one single microprocessor chip for its operations. Desktop PC, Laptop and palmtop computer are microcomputers. Other microcomputers include note books, tablets, game computers, smart books and smart phones, etc.