You can not only stream a live video or audio with SlideSync, you can also upload recordings (video or audio) to an event, put them directly on demand and thus make them available online for your attendees. You can also make files of various formats available for download and of course upload and manage your presentations.
To upload a file (slides, images, recordings or files), click Events in the left main menu, select your event from the list and then click Files.
You can find detailed instructions in this article.