What does "the better part of valor is discretion" really mean?

Question

What does "the better part of valor is discretion" really mean?

Answer 1

It's not a general statement - someone might say it about a particular instance - it means better to STFU than stand up and fight - THIS time in THIS situation.

Answer 2

To me it means that to put valor (bravery) to good use requires discretion (judgement).

Answer 3

It's from Shakespeare and means that it's better to be wisely cautious than foolishly brave--probably because the foolishly brave would accomplish nothing useful even if he proved he was brave, where as the cautious man might accomplish much.