Introduction Internal organization of a digital system is defined by sequence of micro-operations it performs on the data stored in its registers. The general purpose digital computer is capable of executing various micro-operations and, in addition, can be instructed as to what specific sequence of operations it must perform. Now we define basic terminologies: A program is a set of instructions that specify the operations, operands, and the sequence by which the processing has to occur. A computer instruction  is a binary code that specifies a sequence of micro-operations for the computer. Instruction code is a group of bits that instruct the computer to perform a specific operation that is usually divided into parts and the most basic part is the operation