RAM (System Memory) is the place where the computer holds current programs and data that are in use. The term "memory" is somewhat ambiguous; it can refer to many different parts of the PC because there are so many different kinds of memory that a PC uses. However, when used by itself, "memory" usually refers to the main system memory, which holds the instructions that the processor executes and the data that those instructions work with. Your system memory is an important part of the main processing subsystem of the PC,tied in with the processor, cache, motherboard and chipset.