GPIO voltage - 3.3V or 5V?

Total N00B question, but I can’t seem to decipher the datasheet’s info on GPIO voltage. Are they rated for 3.3V input/output or 5V?

I see a listed “MAX” of 5.5V in the “Operating Conditions” section on this page, but unsure what that means exactly.

The IO level is 3.3V. The digital IO pins will allow an input of up to 5.5V without damaging the part. So the Dash could accept a 5V input signal, but it will only generate a 3.3V output.

Sorry for the very delayed response. Missed this post somehow.