# Commonly used auxiliary memories in computers include floppy disks, hard disks, and optical disks.
Auxiliary memory is also called external memory, referred to as auxiliary memory or external memory, and is used to store programs and data that are not currently in the central processor. When the programs and data in the external memory are used, they are transferred from the external memory into the memory.
External storage refers to storage other than computer memory and CPU cache. This type of storage can generally still save data after power is turned off. Common external memories include hard disks, floppy disks, optical disks, U disks, etc.
Common external memory:
Floppy disk: The floppy disk uses a soft polyester material to make a prototype negative, and is coated with magnetic material on both surfaces. Commonly used floppy disks have a diameter of 3.5 inches and a storage capacity of 1.44MB. Floppy disks read data through a floppy disk drive.
U disk: U disk is also called "flash disk" and can store data through the USB port of the computer. Compared with floppy disks, U disks have replaced floppy disks due to their small size, large storage capacity, and ease of portability.
Hard disk: The hard disk is composed of an aluminum alloy original plate coated with magnetic material. Each hard disk is composed of several magnetic discs.
Tape storage: Tape is also called sequential access memory SAM. It has a large storage capacity, but the search speed is very slow, and is generally only used as a data back-up store. There are three types of tape drives used in computer systems: reel tape drives, data streaming tape drives, and spiral scan tape drives.
Optical disc storage: Optical disc refers to a disc that uses optical means to store information. It applies optical storage technology, which uses lasers to write information on a certain medium, and then uses lasers to read out the information. Optical disk storage can be divided into: CD-ROM, CD-R, CD-RW, and DVD-ROM, etc.
The above is the detailed content of What are the commonly used auxiliary memories in computers?. For more information, please follow other related articles on the PHP Chinese website!