RAM, which means Random Access Memory, is a computer storage media that could be accessed much quicker than a hard disk, because the data can be read randomly, skipping the bytes before the needed data is reached. On a server, the RAM is employed to load scripts and web programs once they are executed, so the more RAM you are able to use, the more programs you shall be able to run simultaneously and the more people will be able to look through your sites with no effect on the site’s/server’s functionality. In contrast to a disk drive, however, the RAM is used for temporary storage purposes, as the info is lost the moment the power is shut off. If you use a shared web hosting account, the physical memory that your scripts may use may be limited and may change according to what the some other clients on the same hosting server use. With a virtual or a dedicated web server, alternatively, you'll have a fixed amount of RAM which won't be used by anyone else even when you do not use it at a given time.