A bicycle seat is the part of a bike that you sit on. It's like a chair for your bottom when you ride your bike.
The seat is usually made of some kind of smooth material, like plastic or leather, that doesn't hurt your bum. It's also padded to make it more comfortable for you to sit on for longer periods of time.
The seat is attached to a long, thin metal rod called a seat post, which goes down into the frame of the bike. This keeps the seat in place and allows you to adjust the height of the seat by raising or lowering the post.
There are different types of bicycle seats, depending on the type of bike you have and how you plan to use it. Some seats are wider and more padded for comfort on longer rides, while others are narrower and harder for more sporty, aggressive riding.
So, when you ride your bike, you sit on the seat and pedal with your feet to move your bike forward. It's important to make sure your seat is adjusted to the right height and angle so that it's comfortable for you and helps you ride your bike in the most efficient way possible.