(CNN) It isn't just what you say on social media, often it is where you say it. It may seem like new social media platforms are appearing everyday. Three eight graders who took part in a landmark study on social media, detailed in the " CNN Special Report: #Being13 - Inside the Secret World of Teens ," helped us breakdown how teens use some of the most popular platforms.

Facebook

Facebook is probably the most familiar social platform. The company claims it has nearly 1 billion daily active users, but these three eighth graders say they barely use it.

Facebook's ubiquity could be part of its problem when it comes to engaging with teens like these. Gia from Virginia says she doesn't feel like she can be herself on Facebook, not just because her family is there, but "everyone's family is on there." Selam from New Jersey claims that she only knows one person her age who uses Facebook.

Snapchat

Snapchat is best known for allowing users to send photo messages that are only meant to be visible to the recipient for a few moments.

Zack, who is also from Virginia, uses Snapchat to share his story with his friends and not with his family. He says his parents wouldn't like what he has in his story and he fears his sister would tattle. When detailing some of his recent posts, they included a day with his buddy where they hung out with their girlfriends and ate at Chipotle.

Not everyone Zack interacts with on Snapchat is a friend. He follows some people he doesn't like just to monitor what they are saying about him.

Gia says she uses Snapchat's disappearing messages to send selifes, both cute ones and ugly ones. She also acknowledges that some people use it for inappropriate reasons.

Selam sees the platform as positive, she is aware of situations where people take screen shots of what are supposed to be ephemeral messages and "it's not a good outcome."

Kik

To the uninitiated, Kik may sound like one of the many app alternatives to the text messaging features already built into your smartphone. All three of these eighth graders have unique reasons for using it.

Gia says her friends sometimes prefer to give out their Kik information rather their actual phone numbers. Selam finds it simple to set up group chats in Kik and likes that the platform's profile pictures are an opportunity to share a selfie.

Ask.fm

Ask.fm is an anonymous question and answer platform. It is that anonymity that is too much for teens like Selam who deleted the app. She finds there is too much negativity and some people are are "very vulnerable to it."

Zack is not on Ask.fm either, but he says he is avoiding the platform because he doesn't have any followers and he doesn't want to "start from zero."

Twitter

Selam describes Twitter as "a nice way to let people who you are and how you think." Each post is limited to 140 characters, but that's enough for her to publish "all your rants that you want to let out." She also uses the retweet feature to highlight items that she feels describe her and to let people know about things that she likes.