Secondary storage

Disk Caching

A disk cache is a mechanism for improving the time it takes to read from or write to a hard disk. Nowadays , the disk cache is usually included as part of the hard disk. A disk cache can also be a specified portion of random access memory (RAM). The disk cache holds data that has recently been read and, in some cases, adjacent data areas that are likely to be accessed next.

File Compression

File compression is commonly used when sending a file from one computer to another over a connection that has limited bandwidth. The compression basically makes the file smaller and, therefore, the sending of the file is faster. Of course, when compressing a file and sending it to another computer that computer has to have a program that will decompress the file so it can be returned to "normal" and used.

File Decompression

Data decompression is the reverse--the decoding of compressed data to restore the original.

Internet Hard Drive

The sole purpose of an Internet hard drive is to offer a means of accessing your computer files (pictures, documents, music, videos, etc.) from any computer, as long as that computer has access to the Internet. An Internet hard drive will allow you to "deposit" your computer files into a remote hard drive, and then later access those very same files from any other computer.

Optical Disc Drive

In computing, an optical disc drive (ODD) is a disk drive that uses laserlight or electromagnetic waves near the light spectrum as part of the process of reading or writing data to or from optical discs. Some drives can only read from discs, but recent drives are commonly both readers andrecorders.Optical disc drives are an integral part of stand-alone consumer appliances.They are also very commonly used in computers to read software and consumer media distributed in disc form, and to record discs for archival and data exchange.

Solid-state storage

Solid-state storage is a nonvolatile, removable storage medium that employs integrated circuits (ICs) rather than magnetic or optical media. It is the equivalent of large-capacity,nonvolatile memory.The main advantage of solid-state storage is the fact that it contains no mechanical parts. Everything is done electronically. As a result, data transfer to and from solid-state storage media takes place at a much higher speed than is possible with electromechanical disk drives.