Why does one "Plead Guilty" rather than "Found Guilty" or "Proven Guilty"? [closed]

I am not sure if this is a Language Question or Legal Question, but in instances of news on court case it is always reported that a "Defendant Pleaded Guilty" but this does not clarify if the defendant admitted to guilt by himself or was proven guilty by evidence presented against him. From my understanding may be there are some legal or lingual technicalities that make the reporting so. Can someone explain why it is always that a Defendant pleads guilty rather than proven to be guilty or found to be guilty?

A plea ("guilty"/"not guilty") is entered by the defendant before a trial while the verdict ("found guilty"/"proven guilty") is the result after a trial.

So, if a defendant "pleaded guilty", they have admitted their guilt prior to the trial. Such an admission would remove the need to conduct the remainder of the trial and, therefore, a verdict of "proven guilty" would not be reached. There are circumstances where a plea can be changed during a trial (from "not guilty" to "guilty") which would effectively stop the trial process.

To sum up, if a "defendant pleaded guilty", it is always the case that they admitted to guilt themselves.