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Storage Media And Devices - Coggle Diagram
Storage Media And Devices
Secondary Memory
Optical storage
read and written by laser
data is stored in "pits" burnt by laser
CDs
Compact Disks used to store audio files or device drives
more storage than floppy disks (800 MB)
DVDs
digital versatile disks used to store DVD movies, backups
more storage than CDS (4.5-8.6 GB)
Blu-ray
read by blue laser instead of red laser unlike CD and DVD
Large storage capacity which means it can store HD movies and audios (25-100 GB)
CD-R and DVD-R
only recordable once, then it becomes read only
CD-RW and DVD RW
allows to be read and written multiple times, used in CCTVS
DVD RAM
used to store data that constantly needs to be rewritten like recording equipment (storage up to 10 GB)
pits stand for 0 and flat stands for 1
Magnetic Storage
disk is coated with magnetic material
uses magnetic bits called grains to store data
A magnet changes the polarity of the magnetic field to store data as 0s and 1s
read and written by read/write head
Fixed hard drive
fixed into the computer
stores operating system, system files, hard drive
incorrect shut down can cause to malfunction
Portable hard drive
A hard drive that can be carried around and plugged itno USB drives
used for personal backup and data transfer; more expensive
Magnetic tapes
used by organizations to make backups of networks
large storage capacity, so least expensive but data access is serial and SLOW
Solid State storage
solid state has no moving parts and uses flash memory
based on electronic circuits and stores data by controlling movement of electrons in NAND chips
USB Memory Stick
used to transfer files between computers
small, portable, and robust
Memory card
Store data on digital cameras, phones, and mp3
small and more expensive
Primary Memory
RAM
ROM
Cache
Types of access
Serial access
stored one by one
user needs to go through the whole disc to find one specific data
not in order
Direct access
The user can go directly to the data
not needed to go through the whole disc
Storage medium is the device that holds the data