Q. Describe Memory and Memory unit?

Input devices can fetch instructions or data only sequentially though a program may or may not be executed sequentially because looping, jump, decision-making instructions are frequently encountered in programming. As well more than one data element may be needed at a time. Hence a temporary storage area is required in a computer to store temporarily the instructions as well as the data. This element is termed as memory.

Memory unit stores all information in a group of memory cells like a group of 8 binary digits (which is a byte) or 16 bits or 32 bits and so on. These groups of memory cells or bits are known as memory locations. Every memory location has a unique address and can be addressed individually. Contents of desired memory locations are supplied to CPU by referring to address of memory location. Amount of information which can be held in main memory is termed as memory capacity. Capacity of main memory is measured in Mega Bytes (MB) or Giga Bytes (GB). One-kilo byte denotes 2¹⁰ bytes that are 1024 bytes (or just about 1000 bytes). A Mega byte denotes 2²⁰ bytes that is near about a little over one million bytes and a giga byte is 2³⁰ bytes.