Documentation or Reference on interpretation of Dashboards/Graphs

Hi, I am a beginner to Prometheus and Grafana

Want to understand correct way of interpreting the CPU Utilisation, whose expression is as below
“sum by (name) (rate(container_cpu_usage_seconds_total{image!=”",instance=“”,job=“cadvisor”}[1m])) / scalar(count(node_cpu_seconds_total{mode=“user”})) * 100",

I looking to understand correlating the CPU Usage %age with available CPU, especially for below scenario

If a 2 core machine is showing 1.6% as CPU utilisation, what does it mean ? if i have to extrapolate this to a 4 core or 1 core system, how do we do it accurately ?

I am assuming it is a %age against the cores running on that system, but looking for technically correct definition and formulation

Is there somewhere we can document about it or already it exists