Net neutrality is synonymous with open internet wherein no restriction is imposed on the content or communication mode viewed or used by individuals. In the technical jargon, it implies that the Internet Service Provider cannot block or discriminate against any internet application over its network. In common parlance, when net neutrality is violated by ISPs, it is equivalent to saying that your phone company decides which contacts you can speak to over its network and what you can say.
Why is it important?
Net neutrality promotes free speech and allows us to avail applications that can significantly bring down the amount earlier expended on conventional modes of communication.