It’s important to learn about this because it about where you would like to get your information from and making sure it was the first and accurate source. I’m assuming you mean primary and secondary source when citing something. It can be applied through reality by comparing it to would rather hear news from a reporter(the primary source), at the crime scene or just the location they’re doing their story on, or your parents (the secondary source), who has heard the story multiple times from other family, friends, and reporters.
