In Userflow you make videos by defining manuscripts. Userflow can perform these manuscripts, giving you ready-to-use videos.
You can make as many videos as your plan allows. A video typically covers a single topic, e.g. "How to create an X" or "How to update your Y". Each video has one manuscript, which can be edited as often as you'd like.
When rendering your videos, Userflow performs all the actions you've defined, prepares voice-over and cuts it all into a single video, which you can embed on your website.
You can render each video as many times as you'd like. Videos are typically re-rendered when you update the manuscript or if something on your website/web application has changed and you'd like an up-to-date video.