How to understand computer memory

RAM is a type of computer memory which stands for Random Access Memory. It is made up of small memory chips that form a memory module.

These modules are installed in the RAM slots on the motherboard of your computer. Every time you open a program, it gets uploaded from the hard drive in to the RAM.

This is because reading data from the RAM is much faster than reading data from the hard drive. Running programs from the RAM of the computer allows them to function without any lag time.

ROM stands for Read-Only Memory. It is memory that cannot be changed by a program or user. ROM keeps its memory even after the computer is turned off.

Once data has been written on to a ROM chip, it can not be removed, only read. The memory is also nonvolatile.

There are different types of RAM, including DRAM (Dynamic Random Access Memory) and SRAM (Static Random Access Memory).

Virtual Memory: This is a method of making a computer appear to have more primary memory than it has really has physically.eg. a PC might have 2Gb of RAM as primary memory, but virtual memory of 4Gb.

For instance a PC might have 2Gb of RAM as primary memory, but virtual memory of 4Gb.

Moving pages between virtual and physical memory takes time so the less we do this the better. A computer might spend too much time swapping pages back and forth between physical and virtual memory.

This will slow down the computer. We call this 'disk thrashing.

Flash memory is a type of non-volatile storage. It retains its information even without power. So it is ideal for devices such as cameras.

Advantages: Flash is very tough and will not break when dropped or exposed to heat (it is a solid-state device) It is very reliable as there are no moving parts, the data should be held for decades.

It is very compact and can store gigabytes of data in a small space. It is very fast. As there are no moving parts needed to get to the data it is much quicker than hard disk or DVD.