Storage

Storage

1. Primary Storage Devices

   • RAM
     • Random access memory (or simply RAM) is the memory in a computer that is used to store computer programs while they are running and also any data the programs need to undertake their task. ... RAM is emptied every time the computer is turned off. It is also known as 'volatile memory'
   • Hard Drive
     • a disk drive used to read from and write to a hard disk.
   • ROM
     • Read Only Memory (ROM) ROM is a memory chip where essential system instructions (BIOS) are permanently stored. The data held on ROM can be read but not changed. This is done during manufacturing. ROM is non volatile, meaning that the data stored on it will not be lost when the computer is switched off.

2. Secondary Storage Devices

   • Floppy Disk
     • a flexible removable magnetic disk (typically encased in a hard plastic shell) for storing data.
   • CD
     • Stands for "Compact Disc." CDs are circular discs that are 4.75 in (12 cm) in diameter. ... CDs can hold up to 700 MB of data or 80 minutes of audio. The data on a CD is stored as small notches on the disc and is read by a laser from an optical drive.
   • USB Flash Drive
     • a small external flash drive that can be used with any computer that has a USB port.

3. Virtual Memory

   • memory that appears to exist as main storage although most of it is supported by data held in secondary storage, transfer between the two being made automatically as required.

4. Optical Storage & Magnetic Storage

   • Optical storage is the storage of data on an optically readable medium. Data is recorded by making marks in a pattern that can be read back with the aid of light, usually a beam of laser light precisely focused on a spinning optical disc.
     • CD / DVD
   • Magnetic storage or magnetic recording is the storage of data on a magnetized medium. Magnetic storage uses different patterns of magnetisation in a magnetisable material to store data and is a form of non-volatile memory. The information is accessed using one or more read/write heads.
     • Hard Drive Disk

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