Green

• Green signals the beginning of the race or the resumption of the race after a caution. It tells the drivers it is safe to go back up to speed.
  
  

Yellow

• Yellow means caution and that there is a hazard on the track, usually after a wreck. Drivers must slow down and stay behind the pace car. Yellow flags usually last at least three laps to give drivers time for pit stops.
  
  

White, Checkered

• White means there is only one lap left in the race. The checkered flag means the end of the race. The first driver to pass the finish line under the checkered flag wins.
  
  

Red

• A red flag means all competitors must stop. This includes drivers and the pit crew in the garage. This is usually because of a rain delay or a very bad wreck, and is often followed by a yellow caution flag.
  
  

Black, White X

• The driver receiving a black flag must make a pit stop within five laps to respond to a NASCAR concern, which could be smoke coming from the car, not maintaining a safe speed or breaking a rule. If the driver does not pit within five laps, he receives a black flag with a white X, meaning he is disqualified.
  
  

Blue With Orange Stripe

• A blue flag with a diagonal orange stripe means "move over" and is a courtesy request drivers might ignore. For example, a group of drivers might be asked to move over if the leaders are coming up behind them.