Ok, kiddo, did you know that in the game of chess, when there are only a few pieces left on the board, it's called the "endgame"? And sometimes, people like to study and write books about how to win the endgame. That's called "chess endgame literature."
Basically, these books are like instruction manuals for how to beat your opponent when there are only a few pieces left on the board. They teach you things like which pieces are most important, how to create "pawn chains" to protect your pieces, and how to "checkmate" your opponent (which is when you trap their king so they can't move it anymore).
Some famous chess players, like Bobby Fischer and Emanuel Lasker, wrote their own endgame books that became very popular. So if you want to be a good chess player, it's important to study the endgame and read some chess endgame literature!