RAM, which stands for Random Access Memory, is a computer storage media that can be accessed faster than a hard disk drive, simply because the info can be read randomly, skipping the bytes before the needed data is reached. On a hosting server, the RAM is used to load scripts and web apps after they are executed, so the more RAM you can use, the more programs you shall be able to run all at once and the more people will be able to look through your websites without effect on the site’s/server’s performance. Different from a disk drive, however, the RAM is used for non permanent storage purposes, because the information is lost once the power is shut off. If you use a shared web hosting account, the physical memory your scripts can use may be limited and might change depending on what the some other clients on the same hosting server use. Through a virtual or a dedicated server, alternatively, you shall have a set amount of RAM which will not be used by anybody else even if you don't use it at a certain time.