How does editing work?
I am involved in a question, and an answer was edited three times. Is there a way to see the earlier versions of an answer? I mean is there something like cache in SO?
If the answer was edited within the first 5 minutes of posting then you will only see the last version. This is a grace period of editing after posting an answer.
If the edits were made after the grace period, all the changes are saved and can be viewed by clicking the timestamp in the user card underneath the post.
Take your post for example :
You can see that @gnat made an edit on your question.
If the original poster makes additional edits, only the timestamp will be displayed;
You'll be able to see all the edits that were made on that post, who made them, what the edits were and how long ago they occurred.
This view is available for questions and answers alike!
For further reading you can consult this post from the [FAQ] related to editing :