Secondary Storage

DISK CACHING

A portion of RAM used to speed access to data on a disk. The RAM can be part of the disk drive itself (sometimes called a hard disk cache or buffer) or it can be general-purpose RAM in the computer that is reserved for use by the disk drive (sometimes called a soft disk cache). Hard disk caches are more effective, but they are also much more expensive, and therefore smaller. Nearly all modern disk drives include a small amount of internal cache.

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. The design of data compression schemes therefore involves trade-offs among various factors, including the degree of compression, the amount of distortion introduced (if using a lossy compression scheme), and the computational resources required to compress and decompress the data

FILE DECOMPRESSION

Data compression is the process of making computer files, folders or information smaller than they originally intended to be. Certain types of data compression can be read or used in the compressed form, for example with compressed music formats such as mp3, while other files require decompression for the user to be able to use them. Decompression requires processing power. Decompression of file archives can be achieved on all computers, but live decompression of video requires much more powerful hardware.

INTERNET HARD DRIVE

Internet hard drives have served to offering a creative new solution to the issue of data storage.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. By uploading regular backups of your files, you can remain immune from the dangers of file loss due to viruses or your hard drive crashing; your local computer can be completely destroyed and yet the files which were stored online would remain safe and unharmed.

OPTICAL DISK DRIVE

In computing, an optical disc drive (ODD) is a disk drive that uses laser light 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 and recorders. Recorders are sometimes called burners or writers.Compact discs, DVDs, and Blu ray discs are common types of optical media which can be read and recorded by such drives.

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. Examples include flash memory Universal Serial Bus (USB) devices and various proprietary removable packages intended to replace external hard drives.The main advantage of solid-state storage is the fact that it contains no mechanical parts.