I heard that Photoshop CS2 is being offered for free. Is that correct?
Technically, no. Only customers who legitimately purchased CS2 or Acrobat 7 and need to maintain their current use of these products may use the downloads you are referring to.
They are really, really old and won't run on many modern operating systems anyway.
And that doesn't even cover all of the new things from CS3, CS4, CS5, and CS6. I mean, NONE of the content-aware tools are in CS2 and those things are a breakthrough! Ooh, and the great mask refinement stuff isn't there either.
CS2 won't run on El Capitan or Win10. You would need a really old operating system to use it.
Did CS2 even run on Vista? It was written for XP.
I was able to use CS2 on my old Vista machine. But Mac users didn't have it nearly so good. CS2 requires Rosetta and Apple removed Rosetta from OSX 10.7 (Lion).