Storage
Storage distinct from Memory is commonly referred to as secondary or mass or auxiliary storage allowing non-volatile / permanent storage.
- Secondary storage is required for large volumes of data and also for data that must persist after the computer is turned off.
- The two most common secondary storage mediums are magnetic disk and magnetic tape.
- A magnetic disk in the form of floppy disk is now obsolete but persists as a hard disk.
- Hard disks have high storage capacity and offer fast access to the data they hold.
- Hard disks are often contained in disk packs that is built into the computer so your data stays with the computer.
- External hard disks and other storage mediums such as CD, DVD and Blu-ray, connected to the system via universal serial bus (USB) and the like, have also become common place.
- CD, DVD and Blu-ray are optical disk medium that use a laser beam to read the disk.
- Some optical drives are read only memory (ROM), which means that your computer can read programs from media, but the user cannot save data to them.
- CD/DVD-RW drives and disks are also available allowing users to create their own media by "writing" data such as music and photos to them.
- Magnetic tapes either on reels or cartridges (similar to that of a tape recorder) are mounted on tape drives and are usually used for creating backup copies of large volumes of data because tape is very inexpensive compared to other media.