So imagine you're playing with toys, and you have this toy car that you really like. And you decide that you want to see how fast you can make the car go. You start timing how long it takes the car to go from one end of a room to the other. Then, every time you do it, you write down the time it took.
That's kind of how records work in the National Football League, or the NFL. When a team or player does something really good, we keep track of it and write it down. For example, if a quarterback throws the ball really far and someone on his team catches it and runs all the way to the other end of the field for a touchdown, that's a really good play. We'd write down the name of the quarterback who threw the ball, the name of the player who caught it, and how long the play was (how far the ball was thrown and how far the player ran).
Over time, we write down lots and lots of these really good plays. And eventually, we have a bunch of different categories that we keep track of. So we might have a record for the most touchdown passes thrown by a quarterback in a single season, or the most rushing yards gained by a running back in a single game.
Once we have all these records, we can compare different players and teams to see who did the best. So if a quarterback breaks the record for most touchdown passes in a season, he's considered one of the best quarterbacks ever. And if a team has the most wins in a single season, they're considered one of the best teams ever.
So basically, records are like a way of keeping score in the NFL. We write down all the really good things that players and teams do, and then we use those records to figure out who's the best of the best!