What does an idle CPU do?

In the last post I said the fundamental axiom of OS behavior is that at any given time, exactly one and only one task is active on a CPU. But if there’s absolutely nothing to do, then what? It turns

System Idle Process High CPU Usage [Solved] - Driver Easy

How To Calculate CPU Utilization

What is the Normal CPU Temperature Range (Idle vs Gaming) - Softlay

Limiting powerconsumption in Desktop builds?

Normal CPU Temperature While Gaming and Idle

Why is the AM5 CPU's idle/min power usage is so high compared to Intel ? I know about the efficiency cores in Intel, still couldn't understand the huge gap. AM5 users, how

System Idle Process - Tech-FAQ

Windows 10 Help Forums

16.04 - 3 cpus in idle state and CPU4 50~100% usage - Ask Ubuntu