Tags are a way to organize and filter videos. You can add tags to videos to find them easier later. For instance, if you create videos for multiple podcasts, you can add a tag to each video for the podcast it is for. That way you can filter videos for only one of your podcasts to find them easier.
To add a tag, click the '+ Add Tag' button on the card for your video. Then type in the tag you want to use and press enter on your keyboard to save it.