Thank you for your interest in our courses!
The main difference between the two options is that the Offline Course is a download of our curriculum that you can use on your device while not connected to the internet. The Offline Course also does not come with all of the features of the Online Course. There is no completion certificate, automatic grading, options for instructor support or feedback, etc. The Offline Course is a collection of downloadable files to use on your own while the Online Course is an interactive online course. However, the curriculum is the same between both options.
You can see all the features of the Online Course here: http://online.startasl.com and what's included with the Offline Course here: http://offline.startasl.com.