What's the difference between interval and circuit?

[fitgoddess]

Was wondering what the difference is between interval workouts and circuit workouts, as I noticed cathe separates them out into 2 categories.

 

[Stacy]

Generally, Interval workouts are cardio workouts where a lower intensity period is alternated with a higher intensity period. Circuits generally alternate cardio with weight training.

 

[kathryn]

Here's info on what a circuit is:
http://69.0.137.118/dc/dcboard.php?...ic_id=65638&mesg_id=65638&listing_type=search