Final answer:
The fetch-decode-execute cycle is the series of steps a computer's CPU carries out to run instructions. It begins with a program loading into memory, continues with fetching, decoding, and executing instructions, and is followed by the processor repeating the cycle for subsequent instructions or performing additional operations as necessary until program completion.
Step-by-step explanation:
The fetch-decode-execute cycle is a sequence of steps that a computer's processor follows to execute instructions. Before this cycle begins, a program must be loaded into the computer's memory. This typically involves loading the program from a storage device into RAM (Random Access Memory).
During the fetch phase, the CPU (Central Processing Unit) retrieves, or 'fetches,' an instruction from memory. The CPU then moves to the decode phase where it interprets the fetched instruction and prepares the necessary actions to carry it out. In the execute phase, the processor performs the operation specified by the instruction.
After the execute phase, the cycle repeats for the next instruction, starting with fetch again. However, if there is a need to access data from memory or handle an input/output operation, the CPU might engage in additional sub-steps or cycles like the memory access or I/O operations respectively. Finally, the computer continues to repeat the fetch-decode-execute cycle until the program is completed and the computer is ready to move on to other tasks.