Okay kiddo, so you know how when you have a toy, you don't want anyone else to take it away from you and play with it without asking, right? Well, some people make things like movies, music, and pictures and they don't want other people to take them without permission either.
But, some people still do take them and share them with other people on the internet. This is called file-sharing. It's like when you share your toys with your friends, but instead of toys, it's with music, movies, and pictures.
Odex is a company that makes money by selling things like anime movies, shows, and music. They don't want people to share their things without permission because that means they won't make money. So, they try to stop people from file-sharing by taking actions against them.
Odex might send letters to people who are illegally sharing their things, telling them to stop. They might also take legal action and sue people who keep sharing their things without permission. This means that they go to court and try to get money from the people who did something wrong.
In short, Odex is a company that doesn't want people to share their things without permission, so they take actions to stop it. This includes sending letters and taking legal action.