Classes of computers

Computers come in many different forms, each designed for specific tasks. One common type is the desktop computer, which sits on a table and offers a lot of power for tasks like playing games, watching videos, and doing schoolwork. Another popular type is the smartphone, a small device you can carry everywhere that helps you stay connected through calls, messages, and apps.

There are also very powerful machines called supercomputers, which scientists and researchers use to solve extremely complex problems, like predicting the weather or exploring space. For fun and gaming on the go, people often use handheld game consoles, which fit comfortably in your hands and let you play your favorite games anywhere.

All these different types of computers help us in many ways, making our daily lives easier and more fun. Whether you're doing homework, talking with friends, or exploring new ideas, there's a computer suited just for you.

Classes by purpose

Microcomputers (personal computers)

Microcomputers became the most common type of computer in the late 20th century. They include desktop computers, which sit on or under a desk, and can be very small. There are also rackmount computers that fit into special equipment shelves, in-car computers for entertainment and navigation, laptops and notebooks that are portable, tablets with touch-screens, smartphones and other small handheld devices, programmable calculators for math, video game consoles for home entertainment, and handheld game consoles you can carry anywhere.

Minicomputers (mid-range computers)

Minicomputers are in the middle range of computer sizes, bigger than personal computers but smaller than mainframes. They were often used in businesses and labs and could connect to many users at once. These computers have largely fallen out of common use today.

Mainframe computers

Mainframe computers are large machines designed to handle huge amounts of data quickly. They are used by big organizations like governments and banks to serve many users at the same time.

Supercomputers

Supercomputers are the most powerful computers, used for very complex tasks like weather forecasting and scientific research. They can perform calculations much faster than ordinary computers and are measured by how many operations they can do each second.

Classes by function

Servers

A server is a special kind of computer that provides services to other computers. It is designed to be reliable and can run for many years. Servers can provide many different services. For example, a database server helps store and manage information that other computers need. A file server stores lots of files for many people to use. A web server delivers websites to people when they browse the internet. Servers can also run many different tasks at once using a technology called virtual machines.

Workstations

Workstations are powerful computers meant for one person to use. They often have extra hardware that regular computers do not have, making them better for professional work.

Information appliances

Information appliances are computers made to do one specific job very well, like playing music or taking photos. These are often small, portable devices you can carry everywhere.

Embedded computers

Embedded computers are tiny computers built into other machines, like cars or DVD players. They help those machines work and usually do just one job.

Classes by usage

Public computer

Public computers are available for anyone to use, such as in cybercafes, schools, and libraries. They are often set up to only run specific programs and cannot easily be changed. These computers usually do not keep personal files.

Personal computer

A personal computer is used by one person, who might also own it. This person can access all parts of the computer and can add or remove software. Personal computers usually store the user's files, and the user often needs to take care of regular tasks like cleaning up files.

Shared computer

These computers are used by many different people, each with their own username and password. Even though people log in from different computers, they can still see their own files. These systems often need a technician to keep them running properly.

Display computer

Some computers are just used to show information, like in shops or at meetings. They might have extra features but are mainly used for displaying content and are not for storing important files.

Classed by generation of computer technology

Main article: History of computing hardware

Computers have changed a lot over time, and we can group them by the technology they used:

• First generation computers (1940–1955): These used special parts called vacuum tubes and were slow and used a lot of power. The earliest computers were not very easy to program.
• Second generation computers (1956–1963): These used smaller parts called transistors, which saved space and power.
• Third generation computers (1964–1970): These used Integrated Circuits (ICs), which are tiny chips that hold many parts called transistors. Over time, these chips got better and could hold more transistors.
• Fourth generation computers (1971–present): These use Microprocessors, where many tiny chips are put together on one small piece. This made computers smaller, faster, and able to run on batteries, like in laptops, tablets, and smartphones.