RAM (Random Access Memory Module or random access memory) is a type of memory that computers use to store data and programs that need quick access. This is a type of volatile memory, meaning that clears when you shut down the computer, but there are also non-volatile RAM memory (eg flash memory type. Data stored in RAM is not erased when you shut down the computer, but this should be removed when we use (for example, when we close the file containing the data). These reports have some access times and bandwidth much faster than hard disk, it has become a determining factor for the speed of a computer. This means that, within limits, a computer will be faster the greater the amount of RAM you have installed, expressed in Megabytes or Gigabytes. The memory chips are usually connected to some inserts called modules, but this has not always been so, because up to 8086 computers of the type of RAM chips were welded directly to the motherboard. With 80,386 computers of the type first reports appear in modules, connected to the motherboard via sockets, usually referred to as memory banks, and with the possibility to extend (this, prior to computers, it was virtually impossible). The first modules used were the so-called SIMM (Single In-line Memory Module). These modules had contacts in one of their faces and could be 30 contacts (the first), which later became 72 contacts.