Socialization theory suggests that television teaches us about our world and where we fit in it. It can be seen as a person's introduction into our social life. This theory can be helpful to children or those in a culture other than their own to see how it is socially acceptable to act.
The Uses and Gratifications Theory says that audiences play an active role in choosing the media they will be subjected to and will be gratified by this media. This theory argues that audiences aren't passive and will choose media that will benefit them. An example of this is how we search for different topics on the internet. One may be using the internet to find local news while the other is playing on Facebook to avoid studying.
Agenda Setting Theory tells us that the media tells us what to think about by their placement of a story and the amount of attention given to a particular topic. Let's say your local news station first showed a 15 minute story covering local crimes and then a 5 minute story covering pollution in the city. Which topic would seem like a more prominent problem? The crime in the city would seem like a bigger issue because it was presented first and for a longer period of time. This can be viewed as the media shaping our reality by creating topics of more importance than others. The video below gives a brief description of the Agenda Setting Theory.