The Carnegie Medal is awarded every year to an outstanding children's book.
It also has a sister award, the Kate Greenaway Medal, for the top illustrated book for children.
The main judges are 12 children's librarians from around the UK. But they listen to kids from schools and library groups who read the shortlisted books and give their opinions.
Past winners of the Carnegie Medal include The Other Side of Truth by Beverley Naidoo and Northern Lights by Philip Pullman. Winners are announced in July each year.