on each question page on the left side there is three words "asked" and "viewed" and "active". What is "active"?
Active gives the date/time of last activity that happened on the question/answer. Whether a new answer was added, existing answer/question was modified.
Active lists that last date/time any of the previous condition happen.
If you notice that your question has active on it, and if you move your ,mouse over the word today, it will show you the time and date of last activity