RAM, ROM, and Virtual Memory
RAM
it refers to the type of primary storage that is volatile (loses the data if the power is turned off)
It is possible to directly access any memory location in a random order
Stands for Random Access Memory
ROM
read and write only
stores instructions and data ready for the CPU to execute
If a computer has too little RAM - it runs slower
instructions are loaded into RAM from secondary storage as program is executed and the CPU takes instructions from RAM and executes them
RAM usually has 1-256 GB
read only
it refers to the type of primary storage that is non-volatile
Stands for Read Only Memory
Used to store the BIOS (basic input/output system) - the software which starts the computer before the operating system loads
ROM is ideal for storing instructions and data needed for the computer to run. These instructions can not be overwritten
BIOS runs as soon as the computer is switched on. It checks that the software is functioning correctly, then it runs a second program, boot up or bootstrap program that loads into the computers operating system
VIRTUAL MEMORY
It is the use of secondary storage as additional primary storage
When the amount of RAM needed to hold all running programs and data is greater than the amount of available RAM, part of the computers secondary storage, e.g hard disk, can be used to temporarily store data
The operating system will swap data from the RAM to the virtual memory
When the user needs the data again, the operating system will swap data back from the virtual memory back to the RAM
This process is known as swapping
However, this process is time consuming