Recommended: Check all except 1080p (720p is close enough to 1080p for most purposes).

Reasoning: If you wish to create a Streaming video player (rather than a Standard video player - see the difference here), then you would first go to the Media page, find the name of the file that you wish to stream, and then click on the "Prepare for Streaming" link next to it.

And then, the .mp4 is turned into a video stream, and then later when you create a Shortcode for that video and embed that on a WordPress Page or Post, the video that plays will be a streaming video.

And when you click on "Prepare for Streaming", the video is converted into multiple streams with different resolutions. The most popular, high quality video resolution is 1080p (aka, "Full HD"). Of course there's 2K, 4K, 8K etc, but they're all overkill for for the purposes of an online course.

So 1080p has great quality. But if you want to save costs for yourself as well as your viewers, a slightly lower 720p will also look almost just as great, but while also reducing your delivery costs and saving the viewer's bandwidth.

And then, if you have viewers from countries where internet access is expensive, or they have limited access to it, or is very slow, maybe they're watching on a phone which has even slower acess, and you want them to watch your videos without interruption, without it spluttering and freezing every few seconds, then it is recommended that you offer even lower resolutions for those viewers with restricted internet access. And that means, offering resolutions like 360p, 240p and even 144p.

And when a viewer watches your video, S3MediaVault will automatically switch the resolution to the lowest-but-best resolution for the viewer, this saving them internet bandwidth, and saving you delivery costs.

We recommend these four: 720p, 360p, 240p and 144p. That's why, these 4 are checked by default in the Settings. But feel free to change them if you know why. But if you're not sure, leave all of them checked except 1080p.

Full documentation & setup videos available at S3MediaVault.com/doc/