Progressive Download is a technique wherein video or audio content can be watched at the same it is downloading to a computer or device. This process differs from streaming in that the file is saved to your computer during the process, although sometimes without the user knowing it and sometimes only temporarily.
DaCast uses a strictly streaming approach that does not support
progressive download. The reason for this is due to the large volume of
content that is behind paywalls for which a progressive download
approach would be prohibited and allow people to easily take paid
content and then redistribute it to others.