To make sure you get the most out of the game, we’ve put together some brief guidance around what the on-screen graphics mean during the game.
Let’s start with the teams. The away team and their score is typically shown on the left, with the home team and their score to the right. The marks near each team’s name represent how many of the three timeouts their allotted per half that they have remaining.
Here you see which team has possession of the ball, the direction they’re driving the current down, and how many yards they need to gain for a first round.The white and blue line appears to show viewers where the line of scrimmage is set at. The yellow and white line shows the first down marker the team needs the game.
Here you see that the current quarter is called out, and the game clock which is split into 15 minute quarters is also shown. Also shown, is the play clock which is set at 40 seconds for 25 seconds depending on the game situation.
… and finally, when the play clock runs under five seconds it is highlighted in red.
Source: NFL.com