RAM, that means Random Access Memory, is a computer storage media that could be accessed much more quickly than a hard drive, as the info can be read randomly, skipping the bytes before the needed info is reached. On a hosting server, the RAM is used to load scripts and web apps once they are executed, so the more RAM you can use, the more apps you will be able to run all at once and the more people will be able to explore your sites with no effect on the site’s/server’s performance. In contrast to a disk drive, however, the RAM is employed for short-term storage purposes, because the data is lost when the power is shut off. When you use a shared web hosting account, the physical memory which your scripts may use may be limited and may change based upon what the other customers on the same machine use. Using a virtual or a dedicated hosting server, however, you'll have a guaranteed amount of RAM that will not be used by anybody else even if you do not use it at a particular time.