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Who on earth is downvoting this? Get a grip

They're downvoting because the entirety of your comment was a (baseless) worry about the definition of a word that would have taken seconds to check.

Totally have time to read huge PDF's every day.

It has a section in the wikipedia page, which is right under that PDF in the search results.

Alternatively in the PDF you would only need to look at the "Introduction" section for a minute.