It is fun to explain position names to Brits et al. in CFB.
OK, the center snaps the ball. He's in the center of the line.
He snaps it to the quarterback, who is kind of a quarter of the way back in the I formation.
The next back is the fullback, because, well, I don't know, and then the halfback, even though he's fully back.
In the line, we have an offensive guard to either side of the center, and then tackles, who of course never tackle anyone, or they get a penalty if they do.
Then there is one tight end, he's on the end of either side of the line, but lines up tight.
Then there are two wide receivers here and here, and another guy in the "slot", but only if there is no fullback. And a player can't catch a pass downfield if he lines up and is covered, but his own teammate.