(See drupal.stackexhange.com)

On the main questions page, one key tab are "hot" questions. "Hot" questions are determined by a combination of factors:

Votes [aka Score]
Views
Answers
Answer Votes [aka Score]
Whether the question has an accepted answer or not
Time question was originally asked
Time of last activity on question
Reputation of asker
Reputation(s) of answerers

Hot questions are recomputed every 15 minutes.