The difference between RISC (Reduced Instruction Set Computer) and CISC (Complex Instruction Set Computer) architectures can be summarized as follows:

1. Instruction Set Complexity:
– RISC: Uses a small, simple set of instructions, each executing in a single clock cycle.
– CISC: Employs a large, complex set of instructions, which can take multiple clock cycles to execute.

2. Instruction Execution:
– RISC: Instructions are of fixed length, facilitating easy pipelining and faster execution.
– CISC: Instructions are of variable length, complicating pipelining and potentially slowing execution.

3. Hardware Complexity:
– RISC: Features simpler hardware design, resulting in lower power consumption and cost, making it suitable for mobile and embedded systems.
– CISC: Involves more complex hardware, increasing power consumption and cost but allowing direct memory manipulation and complex operations.

4. Memory Usage:
– RISC: Emphasizes software complexity, often requiring more code and memory for complex tasks due to simpler instructions.
– CISC: Emphasizes hardware complexity, often requiring less code and memory as instructions can perform more complex tasks.

5. Design Philosophy:
– RISC: Focuses on executing simple instructions quickly.
– CISC: Aims to reduce the number of instructions per program, prioritizing overall program efficiency.

In essence, RISC prioritizes speed and simplicity with a streamlined instruction set, while CISC focuses on reducing the instruction count per program with a more intricate instruction set.