What is the difference between a direct and indirect address instruction how many references to memory are needed for each type of instruction to bring an operand into a processor register?

Direct address instructions specify the memory location of the operand directly within the instruction itself, requiring only one memory reference to fetch the operand. In contrast, indirect address instructions specify a memory location that contains the address of the operand, necessitating two memory references: one to retrieve the address and another to fetch the operand itself. Therefore, direct addressing is more efficient in terms of memory access.