Meaning of 230v AC supply and rms voltage

Root mean square value of 230v AC supply is 230 V.

This mean that time-averaged power delivered is equivalent to the power delivered by a DC voltage of 230 V.

Voltage_peak = √2 x Voltage_rms

So peak voltage 325 volt. During the course of one cycle the voltage rises from zero to 325 V, falls through zero to −325 V, and returns to zero following sine waveform.