Here's a question: "What's the difference between an offside, a false start, and an illegal shift"
Let's start with an offside call. Offsides is called 99% of the time on the defense, and it is committed when a defensive player moves across the line of scrimmage (the blue line on TV). There is an area about half a yard from the end of the football that's called the "neutral zone" (not to be confused with what the Romulans and the Federation had between them, but similar) that serves as a buffer between the offense and the defense. If he crosses through the neutral zone and makes contact, he is offsides.
A related call is when the defensive player actually lines up with part of his body in the neutral zone. Technically that's a neutral zone infraction, but will often be called offsides. The resulting penalty in either case is five yards, against the defense, and the offense gets the down over.
Both a false start and an illegal shift are called on the offense. And similar to the defensive calls, these result in 5 yard penalties, but against the offense, and the offense gets the down over.
A false start can be committed by anyone who is along the offensive line, including linemen and tight ends in a three-point (both feet and one hand on the ground) stance. If they set into position and move before the ball is snapped, they will be called for a false start. There are some exceptions for a line shift (if more than one player as a result of a change in formation, and they set for 1 second before the snap), but basically that's the rule.
In general, an illegal shift is committed by any other member of the offense, but typically they'll call this if two players move at the same time (you can have one man in motion before the snap) or someone moves in a way that "simulates a snap" (usually, that means they head upfield - even from the backfield - without crossing the line of scrimmage).
There are som unusual cases where they will call offsides on an offensive player, and that would happen when a player - such as a wide receiver - leaves the line of scrimmage and crosses the neutral zone.