RAM, or Random Access Memory, is a sort of computer data storage, that allows the data to be read randomly without accessing the preceding bytes before that. That makes the RAM noticeably quicker than other sorts of storage devices like DVDs or HDDs where all of the data needs to be read so that you can access specific info. If you have a shared hosting account, the total amount of memory your web apps can use can't be fixed and may sometimes depend upon the free memory which is available on the physical machine. When using a standalone web server, however, there is always a minimum amount of physical memory that shall be available at all times and will not be allocated to other clients even if it's not in use. That is valid with our virtual and dedicated servers.