RAM is abbreviation for Random Access Memory. RAM is also known as Primary memory or Primary storage of data of a computer. It does not store any data permanently. RAM can only store data until a computer is switched ON.
RAM is used to store data temporarily so that the processor can access and process data.
RAM stores data until the processor access and executes it, then it is deleted and new data is loaded. RAM is also a very necessary part of a CPU because a computer cannot start if there is no or very very less RAM installed or even when it is loosely placed inside.
Today's RAM technology goes by the name DDR SDRAM which stands for Double Data Rate Synchronous Dynamic Random Access Memory. Most widely used RAM in today's world is DDR3 which is again being replaced by DDR4. These are terms used to define technology used in RAMs which depicts their speeds.