Choosing The Ram

RAM is an acronym for Random Access Memory that is also known as volatile memory, because the data it holds is lost when the desktop PC or laptop/notebook computer using it is switched off. Briefly, RAM memory is used by the system to store data in the form of files for processing by a computer's central processing unit (CPU), also known as the processor. The processors used in most PCs are made by Intel and AMD. The processor runs the program and data files according to instructions given to it by the operating system, which, on PCs, is usually a version of Windows, or, to a much lesser extent, a version of Linux

Unless all of the memory slots on a computer's motherboard are already fitted with memory modules, the RAM memory in most desktop and laptops computers can be increased by installing more memory (upgrading the memory). Installing one or more additional memory modules in a desktop or a laptop computer is a simple process that is dealt with at the top of Page 2 of this article.

Some high-speed RAM memory modules come with passive heatsinks fitted to them. These heatsinks can also be purchased. Names for memory cooling devices are heatspreaders, heat spreaders, ramsinks, memory cooling kits, RAM heat sinks, etc. You can find vendors for them by entering these names in the Google search box at the top of this page (with its Web radio button enabled).
source : http://www.pcbuyerbeware.co.uk/RAM.htm