memory and storage

shifting

moving binary values left or right

RAM (random access memory)

\-high speed

\-volatile (temporary)

\-main memory on computer

\-when it boots up operating system is copied from secondary storage to RAM

\-when applications, files, etc are opened they are copied from secondary storage to RAM

\-RAM is faster than secondary storage

virtual memory

\-secondary storage (not primary)

\-not physical

\-stores data which is not in use to free up the RAM

\-moves the data back and forth from the virtual memory to the RAM as and when the data is being used

memory

fundamental part of a computer. contains all of the instructions that the CPU follows.

ROM

\-read only memory

\-non-volatile

\-contains the instructions to run the BIOS (basic input output system)

volitile/ non- volatile

data is only kept when data

flash memory

\-solid state

\-non volatile

\-ability to be electronicallu reprogramed and erased

\-often found in USB flash drives, MP3 players, digital cameras and solid-state drives

secondary storage

\-long term storage

\-refers to the hard drive

\-non-volatile

\-holds more data than main memory

\-stores data which is not in use

data capacity

how much space is there to store files?

optical

e.g Cd, Dvd

uses a laser light to write to the disk using a pattern

magnetic

magnetic strip such as floppy disc. are read using a moving head inside the disk drive. the tape is read sequentially (beginning to end)

solid state

\-SSD (solid state drive)

\-no moving parts

\-fastest read/write speed

\-referred to as flash memory e.g USB

speed

how quickly can the computer read data from the storage device and write data to it

portablity

can you easily unplug it and carry it away?

durability

how easily it is to damage? will it surivie dropping

reliablity

how long it will last

cost

storage decides vary in cost per Gb

cloud storage

\-saves data in an off-site storage system

\-not physical

\-e.g icloud, dropbox

\-via the internet

\-includes own security, backups, log ins

bit

binary digit, the smallest unit of data store by a computer. each bit is represented by a binary number 1= true or 0= false

nibble

4 bits, two nibbles would be equal to a byte

byte

contains 8 bits e.g 11001010

kilobyte

1KB = 1,000bytes

megabyte

1MB= 1,000KB= 1,000,000 bytes

gigabytes

1 GB = 1,000 MB= 1,000,000 KB = 1,000,000,000 bytes

terabyte

1 TB = 1,000 GB = 1,000,000 MB= 1,000,000,000 KB = 1,000,000,000,000 bytes

petabyte

1 PB= 1,000 TB= 1,000,000 GB = 1,000,000,000 MB= 1,000,000,000,000 KB = 1,000,000,000,000,000 bytes

binary

128 64 32 16 8 4 2 1

0 (flase) and 1 (true)

HEX

0-9 is denary and A- 10, B-11, etc

charters

any options on the keyboard. unit of information.