Secondary memory

Secondary memory – Secondary memory is a type of computer memory that is not directly accessed by the central processing unit (CPU) of a computer and is usually available as non-volatile memory. One of the most common forms of this memory is the hard drive of a computer, which is used to store the operating system (OS) and other programs. Other forms of secondary memory include disc drives for compact discs (CDs) or digital versatile discs (DVDs), as well as removable flash memory.

• Hard Drive – a rigid non-removable magnetic disk with a large data storage capacity.
• Floppy disk- A floppy disk, also called a diskette or just disk, is a type of disk storage composed of a disk of thin and flexible magnetic storage medium, sealed in a rectangular plastic carrier lined with fabric that removes dust particles. Floppy disks are read and written by a floppy disk drive (FDD).
• Magnetic Tape – Magnetic tape used in recording sound, pictures, or computer data.
• Flash memory – a kind of memory that retains data in the absence of a power supply.
• Optical disk – an electronic data storage medium that can be written to and read using a low-powered laser beam.
• CD-ROM: “Read Only” (used for distribution of commercial software, for example) Standardstorage capacity is 640MB.
• CD-R (or CD-WORM): “Write Once, Read Many” times
• CD-RW: rewritable multiple times
• DVD: similar to CD, but with significantly larger storage capacity (4.7 GB)
• Write once read many (WORM) describes a data storage device in which information, once written, cannot be modified

Mother board – A motherboard is the main circuit board inside a computer that connects the different parts of a computer together. It has sockets for the CPU, RAM and expansion cards (e.g. discrete graphics cards, sound cards, network cards, storage cards etc)… and it also hooks up to hard drives, disc drives and front panel ports with cables and wires.Also known as mainboard, system board.

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