High-occupancy toll lane

Okay, kiddo, imagine you're in a car on a road that has a special lane just for cars that have a lot of people in them. This lane is called a high-occupancy lane, or HOV for short. Now, imagine that instead of just letting cars with lots of people use this lane for free, the people in those cars have to pay some money to use it. This is called a toll - it's like paying a fee to use the special lane. When you combine a high-occupancy lane with a toll, you get a high-occupancy toll lane, or HOT for short.

So, in simpler terms, an HOV lane is a special lane on the highway for cars with lots of people in them, and a HOT lane is an HOV lane that lets people pay money to use it even if they don't have a lot of people in their car.