What does the "lost-and-found" mean?

Native speaker’s answer
Rebecca
"Lost-and-found" is the designated place where lost items are stored so that the owners can retrieve them again. Ex: I found my old cap in the school's lost-and-found! I thought it was lost forever. Ex: Let's put this wallet in the lost-and-found in case anyone goes back for it. Ex: If things stay in the lost-and-found for, like, a month, they throw it away.