STORAGE

•Storage holds data, instructions, and information for future use

•A storage medium / media is the physical material on which a computer keeps data, instructions, and information

STORAGE CAPACITY

•Capacity is the number of bytes a storage medium

can hold

Capacity Storage Measured in 

•Kilobytes = 1,024 bytes,

•Megabytes = 1,024 Kilobytes

•Gigabytes = 1,024 Megabytes

•Terabytes = 1,024 Gigabytes

STORAGE DEVICES

•A storage device is the computer hardware that

records and/or retrieves items to and from storage

media

•To store data and programs when they are not being

processed.

•Stores files permanently.

•Available in the form of hard disk, CD, USB drive,

 etc.

TYPES OF STORAGE

•Magnetic Storage

•Optical Storage

•Flash memory

MAGNETIC STORAGE

–Uses different patterns of magnetization on a magnetically coated surface to store information.

–Examples of magnetic storage are:

       Hard Disk

       Floppy disk

HARD DISK

•A hard disk contains one or more inflexible, circular

platters that use magnetic particles to store data,

instructions, and information

•An external hard disk is a separate free-standing hard disk that connects to your computer with a

cable or wirelessly

•A removable hard disk is a hard disk that you insert and remove from a drive

•Internal and external hard disks are available in miniature sizes (miniature hard disks)

OPTICAL DISCS STORAGE

–Stores information in deformities on the surface of a

circular disc and reads this information by

illuminating the surface with a laser diode and

observing the reflection.

–Types of optical disc are:

»Compact Disc (CD)

»Digital Video Disc (DVD)

»Blu-ray Disc (BD)

•A CD-ROM can be read from but not written to

      -Read from a CD-ROM drive or CD-ROM            player

•A CD-R is a multisession optical disc on which users can write, but not erase

•A CD-RW is an erasable multisession disc

-Must have a CD-RW drive

•A DVD-ROM is a high-capacity optical disc on which users can read but not write or erase

-Requires a DVD-ROM drive

•A Blu-ray Disc-ROM (BD-ROM) has a storage capacity of 100 GB

•DVD-RW, DVD+RW, and DVD+RAM are high-capacity rewritable DVD formats

FLASH MEMORY STORAGE

•Flash memory chips are a type of solid state media and contain no moving parts

–Examples of flash memory storage are:

1) solid states drives

2) memory card

3) USB flash drives

SOLID STAES DRIVES

•Solid state drives (SSDs) have several

advantages over magnetic hard disks:

    -faster access time

    -faster transfer rates

    -generate less heat and consume less power

    -last longer

STORAGE CAPACITY DIFFERENCES TABLE

(between magnetic, optical and flash memory)

COMPARE MEMORY AND STORAGE