Explain to me...

It means you will not contest the charges against you. It sometimes means the evidence is so overwhelming that you can't put up a decent fight. Sometimes it's used as a plea agreement for a reduced sentence or to avoid a lengthy trial.

"No contest" (nolo contendere) is a plea made by a criminal defendant. It means that the defendant will not contest the state's charges. In practice, this is like a "guilty" plea, in that the defendant does not go to trial but instead accepts the sentence imposed by the court.

The only reason that a defendant would plead "no contest" is that, unlike a "guilty" plea, a "no contest" plea cannot be used as an admission of culpability in a subsequent civil trial.