What is a false start in football?

My wife and I were watching football a few weeks ago and there was a false start. She's a big baseball fan and so am I, but it's taking her a little longer to pick up on the rules of a few other sports.

A flag was thrown for a false start. She asked what that meant and I explained that a false start happens when an offensive player not already in motion moves before the ball is snapped. This seemed like a pretty simple, one-sentence summary without getting into too many details about how one person can be in motion and...well, you get the picture. I told her the reason for prohibiting movement was so you didn't try to draw the defensive players offsides.

She became confused as this related to the defensive players. I realized pretty quickly that she was applying backyard football rules to the NFL.

She said, "Doesn't it work like this? 'Ready, set, hut!' And then the defense goes, 'One apple, two apple, three apple, four apple, five apple, and THEN you can rush.'"

I wanted to dive into the difference between a rush and a blitz, but why? Besides, technically the defense is rushing. After all, it is called a bull rush.

Regardless, I was too busy laughing to answer the question for a few minutes after that. I love the candid, honest innocence of my wife.

And she knows me too well, as through my laughter she noted, "You can put that in your blog, too."