Hi @LSmallwood! Welcome to the Community-- happy to have you here 
Depending on where you are embedding the video, the playback behavior can vary. Each browser supports different file types and, in some cases, will download the video file instead of playing it in the browser. Videos uploaded as .mp4 files are supported in most browsers and will play in the browser. You can learn more about adding videos to HubSpot content.
Let me know if I did not understand your questions or if you need additional clarification!
Best,
Kennedy