Video mixing software will allow you extremely useful flexibility over your video (and audio) output that you send to an online event/meeting. You can think of it as a module which sits between your computer and the event software (e.g. Zoom), and appears as a virtual webcam in the list of options.
For example, you could send:
- just your webcam
- your webcam in the corner of a live presentation
- a timer superimposed on your webcam
- a live webpage
- a spinning semi-transparent dodecahedron, with the words "Back Soon". [yes, I have done this]
Some common examples are:
- Open Broadcaster Software (OBS) - open-source and free
- ManyCam - limited version is free, otherwise paid-for, several tiers
- eCamm Live (for Mac)
- StreamLabs - free, based on OBS, better set up for streaming
- StreamYard
Some other alternatives are also listed in theTMiL Doc.
The software can also be used for streaming to e.g. YouTube, or even for recording videos, and they can take in inputs from multiple cameras, media files, shared windows/portions of your desktop as well as audio feeds.
You can do worse than just downloading the software and trying things out, and there's plenty of online guides to learn how to use it - if you have specific questions, ask Katie & Ben.
Here's a video of Ben demonstrating some features: