Missile lock-on is when a missile knows exactly where to go to hit its target. Think of it like a game of catch with a friend. When you throw the ball, you look at your friend and try to aim the ball at them. But if they move, you might have to adjust your aim to throw the ball where they are now.
A missile works the same way. It has a special device called a seeker that can see the target and follow it, even if the target moves. Just like you adjust your aim when your friend moves, the missile will adjust its direction to keep following the target.
When the missile gets close enough to the target, it will explode and that's how it hits it. It's like throwing a ball and having it explode when it touches your friend.
But missiles need to be very careful not to hit the wrong thing. So they have something called a "lock-on" process that makes sure they are targeting the right thing. It's like making sure you're throwing the ball to your friend and not someone else nearby.
Overall, missile lock-on is about making sure missiles reach their intended target by following it closely and using a special process to ensure accuracy.