RAM, that means Random Access Memory, is a computer storage media which could be accessed way quicker than a disk drive, as the data can be read randomly, skipping the bytes before the needed information is reached. On a web server, the RAM is used to load scripts and web programs when they are executed, so the more RAM you are able to use, the more applications you will be able to run all at once and the more people will be able to surf your Internet sites without effect on the site’s/server’s functionality. In contrast to a disk drive, however, the RAM is employed for non permanent storage purposes, as the info is lost once the power is shut off. In case you use a shared web hosting account, the physical memory your scripts can use may be limited and can change based upon what the some other clients on the same machine use. Using a virtual or a dedicated server, however, you shall have a guaranteed amount of RAM which won't be used by anybody else even when you do not use it at a given time.