pipelining in computer architecture

1Stage 1 (Instruction Fetch)
2In this stage the CPU reads instructions from the address in the memory whose value is present in the program counter.
3Stage 2 (Instruction Decode)
4In this stage, instruction is decoded and the register file is accessed to get the values from the registers used in the instruction.
5Stage 3 (Instruction Execute)
6In this stage, ALU operations are performed.
7Stage 4 (Memory Access)
8In this stage, memory operands are read and written from/to the memory that is present in the instruction.
9Stage 5 (Write Back)
10In this stage, computed/fetched value is written back to the register present in the instructions.

1Pipelining is a technique where multiple instructions are overlapped during execution. 
2Pipeline is divided into stages and these stages are connected with one another to form a pipe like structure.