They used to teach this in universities a decade ago (no longer, for obvious reasons). His speech is an example of a PRIMARY source, it is everything in its entirety, the direct content. A SECONDARY source is any information that has passed through someone or something else: articles, summaries, news segments, etc. These are easier to digest, but will not convey the entire story and will surely be subject to bias.

Not only have I had many professors these days decree that we do not need to know any of this, these are also the same people that rely on SNL sketches to teach politics and other historical events.

Now we have a bunch of social media brain rotted people that now exclusively rely on reading headlines and calling it "research"