There are basically three classifications :
Social Publishing: In this platforms, we will publish the content and will upload the videos. Some of them are Blog and YouTube.
Social Networking: In this platforms, we can chat and can make conversations with the public. In this, our goal is to connect with the maximum audience, and though that we can create the content from the conversation.
Photo based Social Networking: In the platform, we interact with the audience with the help of pictures and videos.