Hey kiddo! Do you know that the world is so big that it takes a lot of time to travel from one place to another?
Because of this, people came up with a way to have different times in different parts of the world. We call this "time zones". It's like having different clocks for different places so that everyone knows what time it is even if they are far away from each other.
So let's say you live in New York and your friend lives in California. Even though you and your friend are in the same country, you both have different times because you are in different time zones.
Now, if you want to talk to your friend on the phone, you have to make sure you are calling at the right time. You don't want to call them in the middle of the night when they are sleeping. You need to know what time it is in their time zone so you can plan the phone call.
So that's what time zones are, kid! It's just a way to make sure that people all over the world have different times and can talk to each other without getting confused.