Minicomputers are used by smaller businesses to handle their data processing or to run something similar to a city traffic control system. Desktop computers would naturally be supplied with the computer itself (complete with hard disk drive and floppy disk drive) and peripherals such as a screen, a mouse, a keyboard and a CD or DVD drive. These are comparatively cheap and easy to add development cards to. The only disadvantage is that it takes up lots of space and is not easily moved.
Notebooks (Laptops) These are little, light and simple to carry around. You open it by his hinges and has a screen on its inside, keyboard and mouse controls. These are really expensive because of their processing power and you cannot use standard expansion cards. Keyboards and screens not as good for extended usage. They are designed to run on rechargeable batteries or the mains and can contain many of the description available on a desktop computer.
Touch pads or a button are usually used to control the screen pointer. These are also portable due to their size and ability to run on batteries Palm-tops & PDAs (personal digital assistants) These are very portable, small hand-held computers. They are usually supplied with software such as a diary, a contacts database, and some form of word processor. Many now have email facilities and even spreadsheets and databases. They either use a little keyboard or a touch-sensitive screen and writing recognition software.
They can be linked to larger computers straight by cable or through a docking station or using an infrared link. These are relatively expensive, limited expansion; non-keyboard versions can be slow to input data. Embedded computers have a vast number of modern devices contain some figure of built-in computer. Examples include: washing machines; camera, hi-fi systems; telephones; microwave ovens; missiles. The inputs are usually sensors so a keyboard may not be needed. The outputs are usually simple displays or motors and relays to control something.