What is social media?
A social network is an online network of people and companies that communicate and share online. LinkedIn is the largest professional and business social network, whereas, Facebook is a personal social network but with significant business opportunities also.
Micro blogging is the ability to send short messages, normally 140 characters, to one or many people at the same time. An example of a micro blogging website is Twitter.
A business that uses social media effectively will get consumers marketing to other consumers. One way of doing this is making the facility available for users to interact with each other by providing recommendations and ratings for products or services. An example of the effectiveness of this is Amazon. They rely significantly on the user review process to drive sales.
Blogs are online journals where the author can write (blog) about any interest or topic they want. The blogger can also use the blog to share content picked up from other social media sites (e.g. YouTube) by taking advantage of the facilities available to easily share content.