The courses are big, really big, and they take you through a wide range of skills necessary to play your instrument. The workshops are about bringing the focus in a little closer, to one specific area of study and really examining it closely.
The workshops are specific to one thing. It may be a technique such as fingerpicking or using a slide. It may be about improvising, or a practice routine, or chord building or some aspect of theory or musicianship.
Videos would typically be between 30 and 90 minutes long. You're sitting down with me at home with your guitar and honing in on a specific area of study. You can download it and use the free VLC player to loop sections and slow things down, there'll be a workshop on how to do that real soon.
As always there are opportunities for discussions around the topics in the workshop. The forums have a dedicated space for workshops and with each one I'll open a new thread just for that purpose.