Terrestrial television, also known as broadcast television, is any TV channel that you can watch using an antenna. Imagine an antenna as a stick on top of your TV that can pick up invisible signals in the air. These signals carry TV programs, and your TV turns them into pictures and sounds that you can watch.
Many TV stations use terrestrial television to broadcast their shows. These stations have big antennas called transmitting towers that send out signals to the area around them. The farther you are from the tower, the weaker the signal gets, so you might need a taller antenna or a stronger signal booster to pick up the channels.
When you turn on your TV and scan for channels, your TV looks for signals in the air and identifies the channels it can pick up. Each channel has a specific number, like 2 or 7 or 11, that you can use to change the channel. You can also use a remote control to do this.
Some channels are free, which means you don't have to pay anything to watch them. Other channels are "pay-TV," which means you have to pay a subscription fee to watch them. Terrestrial television has been around for a long time, and it's still popular today, especially in areas where cable or satellite TV service may not be available.