Okay kiddo, imagine you have a bookshelf with lots of different books on it. Well, a bibliography is like a big list of all the books someone has written or worked on throughout their life.
Clark Ashton Smith was a very smart and talented man who wrote lots of books, poems, and stories. People really liked his work and wanted to keep track of everything he wrote. So, they made a big list called a bibliography that shows all his works.
This list includes the names of all his books and stories, the dates they were published, and sometimes even where they were published. This way, people can find and read all of his work easily.
It's kind of like a cheat sheet for someone who really likes Clark Ashton Smith's writing and wants to know everything he's ever written. And now that list is available for everyone to see!