Historically, a computer is any device that can store and process data. Today it usually refers to an electronic device with circuits that allow for data to be manipulated in binary form. So the main components are software (memory and programs to process data) and hardware (devices used for the storing and processing of that data). And, lastly, an array of components for humans to interact with the electronic data 'machine.'
Modern personal computers usually contain the following components:
- A Motherboard - The backbone of the computer, designed to transfer information and power to and from all of the major components. Other components are usually plugged into this device, and it is almost always the largest board in the computer. Also called a "Mainboard" or "mobo". The motherboard contain the BIOS (Basic Input/Output System) that allows all the components to communicate with each other.
- CPU (Central Processing Unit) - The Central Processing Unit that is usually attached directly to the motherboard. It is comprised of a chip with usually dozens of pins which are connected to the motherboard. They are usually obscured by a large heat sink (large metal components which divert heat away from chips).
- RAM (Random Access Memory) - Usually Dual-Inline Memory Modules (DIMMs), they are plugged directly into the motherboard as well. Some high-performance versions are cased in metal which help cool the chips on them. There are usually 8 chips on a stick of RAM (random access memory), sometimes there is a 9th "parity" chip, which helps check for errors within the memory.
- ROM (Read Only Memory), usually on a Hard drive - This is usually a large metallic rectangular prism-shaped device about 3.5 inches wide. It stores data onto metal discs within the device and have recently come out with capacities as large as 1 TB (Terabyte, or 1000 Gigabytes, 1,000,000 Megabytes etc). In the 'old days' these were cards, ticker tape, or magnetic discs labeled as A drive or B drive. Now most computers have C drive, which is the hard drive mentioned earlier.
- A Power Supply - Computers need specific power voltages for each component and always have a power supply which takes power from the wall and outputs power at specific voltages on specific cable formats within the computer.
- The OS - The operating system; the primary functions of the operating system are to manage the hardware resources (disk space, memory, CPU and so on) and provide facilities to manage and run programs.
- A case to hold all the components, usually in a tower.
- Human Interface Devices (HID) - These are the components that allow a human being to interact with the computer and access and/or process data. These can include a keyboard, mouse, monitor (digital video screen, usually now an LCD monitor), video cam, microphone, headphones/speakers, graphics tablet, or other devices.
Accessories and Peripherals include:
Optical Devices - It has become common for a computer to contain optical storage devices (such as CD-ROM or DVD drives).
LAN CARD - Known officially as a Network Interface Card (NIC), these devices connect a computer to a network, usually to a router or modem which establishes connectivity to the Internet. These are usually PCI expansion cards or built into a motherboard and output in RJ-45 format. The cable tips (RJ-45) look similar to a phone cable (RJ-11), but are larger.
USB ports -
Printers -
Flash Drives -