RAM, which refers to Random Access Memory, is a computer storage media which could be accessed faster than a hard drive, because the info can be read randomly, skipping the bytes before the needed info is reached. On a server, the RAM is used to load scripts and web programs when they are executed, so the more RAM you can use, the more apps you will be able to run concurrently and the more people will be able to look through your Internet sites with no effect on the site’s/server’s general performance. Different from a disk drive, however, the RAM is used for non permanent storage purposes, due to the fact that the info is lost once the power is shut off. In case you use a shared web hosting account, the physical memory which your scripts may use may be limited and may change depending on what the other customers on the same server use. With a virtual or a dedicated hosting server, however, you shall have a set amount of RAM that will not be used by others even when you don't use it at a given time.