I like the way this article is organized; I learned a lot from it. I can't recall seeing this style of presentation before. To summarize and maybe get you interested:

    All the combinations of having-and-not-having these
    properties gives us 4 interesting kinds of type:

    1. can be used any number of times (no name - the default)
    2. can’t be used more than once (affine™)
    3. must be used at least once (relevant™ - this one is a decent name)
    4. must be used exactly once (linear™)

I don't often dig into type theory, but this article made it fun and interesting!