SoC
State of Charge
How full the battery is right now, from 0 to 100%. It's the EV's fuel gauge, not a measure of its health.
SoC (state of charge) answers one question: how much energy is inside right now? At 100% it's full; at 20%, time to find a plug. It's exactly the fuel gauge.
What it does NOT tell you is anything about the battery's health. A car at 100% SoC can have a worn battery, just as a full tank says nothing about a tired engine. That's what SoH is for.