RAM comes from its acronym in English: Random Access Memory (in Spanish Memory Random Access as defined by AbbreviationFinder), and is a small fast memory performance using the computer to work internally and store data that need quick access. What random access means you can access any part of memory instantly without having to first read the above. The other type of memory is the sequential call, which is obviously much slower, because before reading the third giga must access the first and second. Imagine an audio tape or CD, which rotates on itself and moves back and forth to read one or other party. In the RAM access is immediate, no need to move forward or backward but goes straight to the site in which it indicated that it is the information .
The RAM is a memory as we say, but it has many differences with a memory of a hard drive or flash drive. To begin with , once the computer is turned off or rebooted, the RAM is completely erased. Thus only it serves to store data while the computer is on. Another of his qualities is its speed, much higher than that of a hard disk, a DVD, a memory stick …
RAM is loaded in the operating system generally very beginning of the PC, and then various programs and data that the computer will use while working generally (instructions for video, keyboard, mouse …). Once we start any program, this will be read from disk on which is stored and seek loaded into RAM so that the computer can access it much faster while working. This is what we commonly call ‘load’ a program, and that is why a program usually takes longer to start. Imagine if I had to read data from the disk every time you had to execute an instruction. The program would be very slow.
There are several types of RAM, according to their purpose, and have evolved over time as it has done the computer . In general there are two main types, the DRAM ( Dynamic RAM ) on one side, which is slower because it is dynamic, and therefore must continually refresh, wasting time on it. It is generally the main memory, being cheaper. On the other hand we have the SRAM ( Static RAM ), you need not cool, being much faster, but also more expensive to use transistors instead of capacitors.
In addition to these there are many more types, can be differentiated also according as memory is available, such as SIMM ( Single Inline Memory Module ), which are characterized by putting the memory modules in a row, the DIMM ( Double Inline Memory Module ), which they put them in two rows (and are faster) …, etc.
A special mention should call memory cache , which is nothing more than a small part of the RAM, usually SRAM, which is used for calculations and processes that require quick or needed very often. Pueen also some devices using DRAM to accelerate its processes cache mode, saving data in it until they can be stored in the device. Thus, depending on the device you use it , we can talk disk cache, cache printer … etc …
As we see the main problem of RAM is its small size, it does not always can be loaded into it everything desirable. That is why the amount of RAM can be a limiting as much or more important than the own speed processor , and also the reason that the RAM is the call Main Memory of a computer and is one of the parameters really have into account when purchasing a computer.