Primary sources are artifacts created at the time of the event, issue or person you are studying.
Some examples of primary sources include:
personal accounts (interviews, diaries, letters, etc.)
images (photographs, paintings, maps, etc.)
videos (YouTube, Vimeo, etc.)
Social Media posts (Twitter, Instagram, etc.)
Primary sources are not "best" or "better" than others. They are primary because they allow *you* to analyze them and decide how they will contribute to your research - instead of using the analysis someone else has done.
There are many other examples of primary sources, as well!