RAM, that refers to Random Access Memory, is a computer storage media that could be accessed considerably faster than a hard disk drive, as the information can be read randomly, skipping the bytes before the needed info is reached. On a web server, the RAM is used to load scripts and web applications once they are executed, so the more RAM you may use, the more programs you will be able to run simultaneously and the more people shall be able to surf your sites without any effect on the site’s/server’s general performance. Different from a disk drive, however, the RAM is employed for momentary storage purposes, due to the fact that the data is lost the moment the power is shut off. If you use a shared web hosting account, the physical memory which your scripts may use may be limited and could change depending on what the some other clients on the same server use. Through a virtual or a dedicated web server, however, you shall have a set amount of RAM which won't be used by others even when you do not use it at a given time.