A computer is composed of hardware, not to be confused with software, which is installed on the hardware. The basic computer parts are the motherboard, processor, RAM, hard drive, video adapter and power supply. You have to have all these parts to build a basic computer.
The system unit is the core of a computer system. Usually it's a rectangular box placed on or underneath your desk. Inside this box are many electronic components that process information. The most important of these components is the central processing unit (CPU), or microprocessor, which acts as the "brain" of your computer. Another component is random access memory (RAM), which temporarily stores information that the CPU uses while the computer is on. The information stored in RAM is erased when the computer is turned off.
Almost every other part of your computer connects to the system unit using cables. The cables plug into specific ports (openings), typically on the back of the system unit.
Hardware that is not part of the system unit is sometimes called a peripheral device or device.
The motherboard is the most important part of a computer. Every other computer part connects to the motherboard. If the motherboard does not work, none of the other parts will
The cpu or processor is the computer's brain. It is in charge of telling your computer what computer processes to do and when to do them. It is mounted onto the motherboard along with the RAM.
Random Access Memory, also known as computer memory reads and writes data. RAM does not store information but can remember information while your computer is on. Once you turn off your computer, any information stored in the RAM is erased. The more RAM your computer has, the faster it can run.
A hard drive stores programs, images, and all other files. Unlike RAM, a hard drive stores and remembers information. The video adapter allows your display device to display a picture from your computer. Video adapters are also referred to as a graphics card, video board, video controller, and video card.
A power supply unit supplies power too all of the computer components. Without this you would not be able to turn your computer on.
Your computer's not complete without such peripherals that must be attached to it. One such peripheral would be the Monitor that displays all data. And you cannot give the computer instruction with having a keyboard attached. A Mouse will make this task even easier.