When I ask or answer a question and someone edits my post, how do I accept the edit?
This page in the help center covers everything you might want to know about edits, I think.
To highlight some of the important bits:
- If you're a user with ≥ 2,000 reputation, any edit that you make to a question or answer takes effect immediately:
once you've generated enough reputation, we trust you to edit anything in the system without it going through peer review. Not just your posts—anyone's posts!
- If you are a user with < 2,000 reputation, then any edit you make will be sent to the review queue, where it has to be approved by two reviewers before it takes effect:
These edits remain in a pending state until they get enough votes to either approve them and make the edits take effect or reject them and discard the edit. Two votes in either direction will finalize the action
So, to answer your question, you yourself do not actually have to do anything to accept an edit to your question or answer.1 If it was edited by someone with ≥ 2,000 reputation, the edit will take effect immediately. If it was edited by someone with < 2,000 reputation, then it will take effect iff two users with ≥ 2,000 reputation approve the edit in the review queue.
Note that you can always edit any question or answer that you've written yourself.
- The exception, of course, is if you're a user with ≥ 2,000 reputation and a user with < 2,000 reputation edits your post. Then, it is theoretically possible that you might end up reviewing an edit that was made to your post in the review queue and either approving or rejecting it.