A primary source is generally:
A secondary source, on the other hand:
Whether a source is primary or secondary depends on the context of your research question. Sometimes what we might think of as a secondary source becomes a primary source, depending on how you are using it.
Think about the various kinds of topics that exist within the realm of global media. Then consider what constitutes a primary source or a "text" related to that topic: a twitter feed, advertisements, a screenplay, movie or film reviews, television shows, video games, Congressional hearings, a campaign website, newspapers, films, etc. These can all be primary sources in relation to your topic.