RAM - RANDOM ACCESS MEMORY where all your os basic files, needed app data are put on when you start your system or any app. It's volatile and data is vanished as you turn off your computer. CORE It's a doorway for data to flow into processor. (Again don't think Core i3 mean 3 cores n i5 mean 5 cores) GPU Known as Graphic Card. it's responsible for processing graphical data. It has vRam for storing volatile graphic data.