Why do old questions keep resurfacing?

Question

For example, this question: What's the right terminology for Unity's UI elements?

Answered 5 years ago, was on the front page because somebody updated the answer. And this one: How can I enable remote login in 13.10?

Was "modified by Community" with no apparent changes.

Why do people go around editing old questions that have already been resolved? I understand having up-to-date info, but old questions are for old versions, and usually things change in newer versions.

We're a Q&A site, not a wiki, right?

Answer 1

but old questions are for old versions, and usually things change in newer versions.

That's exactly what editing is for! To quote the help centre:

All contributions are licensed under Creative Commons, and this site is collaboratively edited, like Wikipedia. If you see something that needs improvement, click edit! Editing is important for keeping questions and answers clear, relevant, and up-to-date. (emphasis added)

But a picture is worth a thousand words right?

See that dot in the middle? That is Stack Exchange. So we're both; a Q/A site, and a wiki ;)

Answer 2

The second question was "modified by Community" because it has no accepted answer. The system occasionally bumps questions with no accepted answer onto the homepage (without actually making any change) to give the question additional visibility.