The Comics Code Authority is like a big set of rules for comic book makers. It's like when you play a game and there are rules you have to follow so everyone can have fun and be safe.
The Comics Code Authority was made a long time ago because some grown-ups didn't like the things that were happening in comic books. They thought some of the stories and pictures in the comics were too scary or too rude. So the people who made comic books got together and made some rules to make sure all the comics were okay for kids to read.
The rules said that comic books couldn't have things like too much violence or mean words. They also couldn't show things like drugs, sex or bad things happening to kids. The people who made the comic books had to follow these rules, or they couldn't sell their comics.
The Comics Code Authority is like a big helper, making sure that comic books are safe and nice for kids to read. But nowadays, lots of comic book makers don't follow these rules anymore because they think that kids can understand and handle more complex stories. So some comic books don't have the Comics Code Authority seal on them, because they don't play by the big set of rules.