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

GlassWire Computer Idle Monitor (32 bit) consuming 100% CPU - GlassWire Help - GlassWire Internet Security Forum

Windows 10 Help Forums

Solved: What is the normal idle temperature for my laptop? - HP Support Community - 6118251

Idle Power Use - Balancing Power, Price, and Performance in the Server CPU World

Windows 10 Help Forums

What Is System Idle Process, and Why Is It Using So Much CPU?

What does a CPU do when it's doing nothing?

Idle CPU usage of k3s is high and continuously increases over time

cpu - What is Maximum Frequency, why is it above 100% most of the time, and why is it so high when it should basically be idle? - Super User

AMD Ryzen 7000X3D Power Consumption Spiking Beyond 100 W in Idle Mode

Idle CPU Usage on Grafana seems extremely high: 70,000%+ - metrics - Fly.io

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3 Ways to Fix System Idle Process High CPU in Windows 11

Idle CPU time – 'id' time in top – yCrash