RAM, which means Random Access Memory, is a computer storage media that is accessed considerably quicker than a hard drive, due to the fact that the data 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 applications after they are executed, so the more RAM you can use, the more applications you'll be able to run at the same time and the more people will be able to explore your sites without effect on the site’s/server’s performance. In contrast to a disk drive, however, the RAM is employed for momentary storage purposes, since the info is lost the moment 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 could change depending on what the other customers on the same server use. Through a virtual or a dedicated hosting 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.