Learn about computers today

Hard drives

A hard disk drive (sometimes abbreviated as Hard drive, HD, or HDD) is a non-volatile memory device that permanently stores and retrieves information. There are many variations, but their sizes are generally 3.5" and 2.5" for desktop and laptop computers respectively. A hard drive consists of one or more platters to which data is written using a magnetic head, all inside of an air-sealed casing. Internal hard disks reside in a drive bay, connect to the motherboard using an ATA, SCSI, or SATA cable, and are powered by a connection to the PSU (power supply unit).

Some other computer parts

RAM (Random Access Memory)


Alternatively referred to as main memory, primary memory, or system memory, Random Access Memory (RAM) is a hardware device that allows information to be stored and retrieved on a computer. RAM is usually associated with


, which is a type of

memory module

. Because information is accessed randomly instead of sequentially like it is on a



hard drive

, the computer can access the data much faster. However, unlike


or the hard drive, RAM is a

volatile memory

and requires power to keep the data accessible. If the computer is turned off, all data contained in RAM is lost.


Alternatively referred to as the mb, mainboard, mobo, mobd, backplane board, base board, main circuit board, planar board, system board, or a logic board on Apple computers. The motherboard is a printed

circuit board

that is the foundation of a computer, located at the bottom of the computer case. It allocates power to the




, and all other computer


components. Most importantly, the motherboard allows hardware components to communicate with one another.