Please enable JavaScript.
Coggle requires JavaScript to display documents.
Storage - Coggle Diagram
Storage
Technologies
Solid State - Storage using flash memory. High Capacity, Portability, Robustness but more expensive. Also can only be rewritten a certain amount of times before failure, little warning before failure leads to files easily corrupting.
-
Magnetic - Bits represented by magnets in different states. High Capacity, Low Cost, High Read/Write Speeds (Except tape) but Low Robustness, and can damage/corrupt easy if read/write head collides with disks.
Hard Disk Drive, Magnetic Tape
Optical - Bits represented by pits/no pits. Laser reads optical. Extremely cheap, Very Portable but Low Robustness, easy to break/scratch/corrupt, needs to be specific type if want to rewrite and low capacity. Need specific laser to write. Drive is usually not portable or robust.
Drive reads, disc is media. Drive is storage device.
Cloud - Storage over the internet. Way of accessing storage, not really a technology/device. Data stored in massive, off-site data warehouses which store data that can be accessed and changed over the internet. Usually uses magnetic storage on site. Extremely high portability and capacity but requires internet connection and data security is no longer carried out by user, may be a problem if data is illegally accessed. High capacity may have to be purchased or accessed through a subscription.
Units
-
Byte to anything higher, divide by 1000. To go opposite direction, multiply by 1000.
-
-
Primary
RAM - Volatile, temporary storage of all currently running programs and needed files.
ROM - Non-volatile, permanent storage (Read only) of the BIOS instructions needed to start the computer
Cache- Primary memory within the CPU which holds frequently used or next to be loaded data/instructions. This increases read times as cache has far greater read speed than RAM.
Compression
Lossy Compression - Form of compression which involves permanent loss of data. Usually used with images or sound files as both contain parts which humans cannot always percieve.
Lossless Compression - Form of compression in which patterns in the data are simplified so that the file can be rebuilt while reducing size of file. Less size reduction but no information is lost. Best for text files.
Compression is useful as it reduces storage capacity taken up by files, increases upload/download speed and allows for avoidance of file size limitations in software such as email.
-
-