Publicity is what most PR agencies sell as public relations. It’s the communication of what an organization wants to tell as many people as possible. It’s also known as promotion.
There is little consideration for the audience; often no communication of a value proposition; there’s usually no clear call to action or defined outcome. The nature of publicity means it is, largely, a one way communication.
For more information, here’s a blog post on the topic called ‘Most PR & Marketing is Promotion’ http://ow.ly/sqmPX