What is a 'play clock'?

What is a 'play clock'?

Darrin Chiaverini (Football Coach and Professional Athlete) gives expert video advice on: What's a 'football'?; What is the object of a football game?; How many people are on a football team? and more...

A play clock is a separate clock from the game clock. It basically gives the offense a 25-second clock. And once that clock hits zero, you are flagged for a delay of game. So the 25-second clock was put in place to speed the game up.