Computer systems · Both
CPU & Computer Systems
A computer system is hardware + software working together. The CPU executes instructions in a continuous cycle.
CPU and memory
• **CPU** – control unit, ALU, registers / clock
• **RAM** – fast, volatile working memory
• **Secondary storage** – non-volatile (SSD, HDD, optical, cloud)
• Embedded systems – dedicated computers inside devices
Fetch–decode–execute
1. **Fetch** instruction from memory
2. **Decode** what it means
3. **Execute** the instruction
Repeat. Clock speed and cores affect performance (with other factors).
Practice questions
1. RAM vs secondary storage?
2. Name the three steps of the CPU cycle.