Computer systems may be classified into the following groups:
1 - The supercomputers are extremely fast computers that are used in scientific research for their ability to do large amount of calculations and store large amount of data. One use of these computers is weather forecast because of the large amount of calculations involved.
2 - Mainframe computers allows several thousands of users at any time. They are used by government companies, airline companies for bookings, insurance companies and banks.
2 - Personal computers are for personal use at home or at work. In what follows, the different types of personal computers are discussed.
1 - Desktop
It is a computer system that is used at home, at work, in schools, universities... It consists of a monitor and a casing inside which the power supply, the CPU, the motherboard and many other devices are located.
These computers may be used for creating, editing, printing and sending documents. They are also used to communicate using the vast network of computers spread all over the world called the internet. They are used to play music, videos, games, and learn new languages, mathematics and many other scientific subjects.
2 - Laptop
A laptop has similar computing power as the desktop but has a set of electrical batteries that allows it to be used in cars, parks, airplanes. They also have a smaller weight and are therefore portable. Besides being used to surf the net, send e-mails, they can also be used to create, edit and send documents, excel sheets.
The portability and the computing power of laptops make them suitable for presentations, using for example power point, in conferences and forums.
They also have enough power to play games, read and write CD's and DVD's.
2 - Netbook
A netbook specializes in browsing the Web. They have the looks of laptops, but lack the full capabilities of a computer. They weigh less than a laptop and are smaller in size which are big advantages for travelers with needs to these machines. Almost all netbooks do not have CD / DVD drives. They also have smaller screens and their keyboards are smaller too.
3 - Tablets PC
A tablet PC has the capabilities of a laptop but is smaller in size and does not have a keyboard. It has a touch-screen that allows using fingers or stylus to input instructions and interact with the machine. The keyboard or mouse are not needed. It is light and small in size and is therefore easy to transport.
Modern Tablet PCs allow you to use the internet to look for information and news, watch online videos, read e-books, communicate with your friends, shop online. Tablets are fitted with batteries that may last up to 10 hours. Major advances in technologies such such as battery life, smaller size yet larger memories, touch-screen recognition, and wireless internet access have all contributed to make the use of tablets PC more efficient and practical.
4 - Smart phones.
Besides making telephone calls, a smartphone runs on an operating system and has the ability to let you send and receive e-mails, browse websites on the net and read documents.