The Full form of RAM is Random Access Memory. RAM is a volatile memory means when computer is turned off, that data in RAM are lost. It is the main memory of a computer or mobile phones. You can erase or change your data in RAM. Data or applications currently being used on a device are stored in RAM from the hard drives because data from the RAM are loaded much faster than the hard drives. With the increase in the capacity of your RAM, your computer speed will also increase. It is called ‘random access’ because data can be read and write randomly from any single byte. Generally RAM can be divided into two broad categories i.e. SRAM and DRAM. SRAM is Static RAM which is much faster and more expensive than DRAM. It often functions as cache memory. Information in SRAM is volatile. It stores a bit of data using six transistor memory cell, whereas DRAM is Dynamic RAM is slower than SRAM. It stores a bit of data using a transistor and capacitor pair. As it is less expensive, most computers use DRAM. It is also a volatile memory. RAM is much smaller than hard disk, both physically as well as capacity wise.