An autograph is when someone writes their signature on something, like a piece of paper or a book. This can be a famous person or just someone you admire.
Let's say you really like a singer and you go to their concert, you might want to get their autograph. This means that you want them to write their name on something like a poster or a CD cover.
Autographs can be really special because you can keep them as a memory of meeting someone important or just as a cool thing to have. Some people even collect autographs from different famous people.