What is register?

Register is just like a small memory they are used to store data or bit in binary form 0 and 1 .
A register is a group of flip-flop. Each flip-flop is storing one bit of information. We can use register to store the binary information there are many types of register are- :
1- Accumulator(ACC)
2- General purpose register
3- Pointer counter(PC)
4- Stack pointer(SP)
5- Instruction register
6- Temporary register
7- Index register
8- Instruction formate