A bronze medal is a special kind of reward given to people who do really well in competitions or events. It is usually made out of a special type of metal called bronze, which looks a little bit like gold but is a little bit darker and not quite as shiny.
So, let's say you were in a race with a lot of other people, and you came in third place. That means you did really well, but two other people were faster than you. But even though you didn't win the first or second prizes, you still get a special prize called a bronze medal to show that you did really well and that you did better than most of the other people who were racing.
Sometimes, people have a whole bunch of competitions all at once, like in the Olympics, and if you win the bronze medal in one of those competitions, it means you're one of the best in the entire world at that particular thing! It's like getting a gold star in school, but way cooler and more special.