RAM, that means Random Access Memory, is a computer storage media that can be accessed considerably quicker than a hard disk, as the information can be read randomly, skipping the bytes before the needed information is reached. On a hosting server, the RAM is employed to load scripts and web applications after they are executed, so the more RAM you are able to use, the more programs you'll be able to run concurrently and the more people shall be able to look through your websites without effect on the site’s/server’s general performance. Unlike a disk drive, however, the RAM is used for temporary storage purposes, because the information is lost when the power is shut off. In case you use a shared web hosting account, the physical memory that your scripts could use may be limited and may change according to what the some other clients on the same web server use. Through a virtual or a dedicated server, on the other hand, you shall have a guaranteed amount of RAM which won't be used by others even if you do not use it at a certain time.