RAM stands for Random Access Memory. It stores memory when your computer is on but loses it when the computer is turned off. A more expensive computer has more RAM that stores more data.
Video - What Does Memory (RAM) Do?
Adding More RAM To Your Computer
Adding more RAM to your computer may make it run faster. The more RAM you have, the more programs you can run at one time. To add RAM you will need an antistatic wrist strap for grounding yourself which will cost about £10. Also, the computer motherboard may need specific RAM sockets to add RAMs to the computer.
How to install RAM Memory in your Computer