Notation confusion: taxonomy, taxonomy term


I have something like this in the config:

    foo1    = "foo1plural"
    foo2    = "foo2plural"
    foo3    = "foo3plural"

and in frontmatter I use

foo1plural            = ["blah1", "blah2"]
foo2plural            = ["bar1", "bar2"]

Until recently I thought foo... being “taxonomy” and blah... or bar... the “taxonomy terms”.
But when setting up the list pages I found that
/foo1plural.html is rendered by the /layouts/_default/terms.html template while
/foo1plural/blah1.html is rendered by the /layouts/_default/taxonomy.html template.

So obviously I got mixed things up and would be grateful if someone could give me some definitions that would help me getting this structured.

What does the word “taxonomy” represent in my above example?
What does the words “taxonomy term(s)” represent in the above example?
Any other keywords important in this context?

(perhaps some confusion may be related to that English is a foreign language to me, also)

From a previous forum conversation; hopefully this makes it clearer:

This is an area I would greatly like to improve in the docs as well. All content-related feedback is welcome. HTH.

Thanks for the link to that other conversation which confirms me in what I am doing.

But I am still not sure

  • what do you call “taxonomy”: is it “foo1” or “foo1plural” or “blah1” (I assume “foo1” etc.) or nothing of all that - and if: then what else.
  • likewise: what do you call “taxonomy term”: is it “foo1” or “foo1plural” or “blah1” (I assume “blah1” etc.) or nothing of all that - and if: then what else.
  • what are the correct denominations for the variables in above example in context of taxonomies:
    foo1 = is called ?
    foo1plural = ?
    blah1 = ?

It’s about the wording/the definition, not so much the usage.