“Affirmative action (also sometimes called reservations, alternative access, positive discrimination or positive action in various countries' laws and policies)…”

It calls them the same thing

No. Positive discrimination is a form of affirmative action in various countries' laws and policies. Positive action is another. Positive action is not positive discrimination. Paragraph 2 mentioned merely targeting encouragement for increased participation even if you did not know what positive action meant.

The text attests to both our interpretations.

1) By saying x is sometimes called y under some circumstances, the text implies x (Affirmative action) is equal to or a subset of y (Positive discrimination)

2) The second paragraph also suggests examples of affirmative action that wouldn’t constitute positive discrimination

The text would support your interpretation if the article ended after the 1st sentence. And the 1st sentence did not mention positive action.