Computers usually have four main types of parts: they are different and they perform one of the following functions: input, output, the processing function and the storage one.
The output category includes the devices which allow the computer to send information to you. The normal flow of information for output parts is: computer-> user. This information usually takes the form of sound or sight, but there are new devices which can send information for other senses like skin (touch) and for the nose (for the sense of smell). The common and well known output devices include monitors, speakers and printers.
On the other side, the input devices let you enter information on the computer and generally, the information flow for this kind of devices is user-> computer. This range of computer parts is much wider than the output category and it includes the standard well known keyboard, the mouse, scanners, microphones, light pens or joysticks.
Input devices are the parts that let you enter and manipulate information on a computer. These devices range from the standard keyboard and mouse, to scanners, microphones, joysticks, and light pens.
On the inside, the classic computer has a lot of parts, which work of course as a system. These parts are usually hosted by the computer case (in the case of a desktop computer, the big box hosts all these parts). For iMacs, all the inside parts are built into the monitor case,and the most important of them is the motherboard. It is like the backbone of a computer. All the other individual pieces connect somehow to this central motherboard. The most important elements of the motherboard are the processor chip, the memory and the PCI slots. Everything inside the central unit is connected to the motherboard through sockets which are set up for low-level programming(usually via BIOS). The computer memory is also connected to the motherboard and they work in some sort of symbiosis. All the add-on cards, video, audio, and all the other cards, for printers and for other devices are also connected to the motherboard. A modem can usually be found on the inside of an add-on card.
The processor is the brain of the computer and the most well known processors are Pentium and AMD chips. The processor speed is measured in MegaHertz (MHz) and in GigaHertz(Ghz). They are related measurement units, and 1GHz values 1000 MHz.
The memory is another essential part of the computer, of the hardware components and it is used to store the information temporarily, before it is manipulated by the processor. It is known as the Random Access Memory and abbreviated, everybody heard about RAM. This kind of memory is available only when the computer is turned on and it is measured in Megabytes (don’t confuse with MHz, which represent speed).
PCI slots are some outlets on the motherboard and they allow you to install extra components like sound cards, modems, video cards, and other kind of devices.
In the storage category we have the hard drive and the floppy drive, and the storage solutions have developed very fast in the last years. The hard disk is a device which has as main role information storage. This kind of memory is permanent and it exists even if the computer is turned off.
The floppy drive is available for a portable storage solution, the floppy disk. This disk can store data from one computer and you can move it on another computer. If you own an iMac, you will not have such a drive. Floppy disks, which nowadays have been successfully replaced by CD’s and other innovative storage solutions, were 3 1/4 inches in size and they could store 1.44 Mb of data.