Here are the different forms and types of Social Media;
Social Networking- it is the most casual form of Social Media. Facebook and Twitter are the two biggest examples that almost everyone is familiar with.
Forums- it is a part of a website that allows people to interact and create conversations wit their opinions, advices and help.
Microblogging- you can express your thoughts and opinions using this sites that usually allow users to post and send 140 character messages. Twitter is an example of a Microblog.
Video Sites- are sites that allow people to upload and watch videos online. Sites like YouTube and vimeo, are example of video sites.
Search Engines- not that familiar form of social media.