A preset saves your project's style, so every video can look the same.
Saving one
Open Presets at the top of the editor and choose Save Current as Preset…, then name it. A preset keeps the background, frame, cursor, camera, captions style, key overlay, voice setting and animations.
Using one
Open Presets and click its name, or type its name in the command menu (⌘K) as Apply Preset. Your project's aspect ratio, crop and volume stay as they are.
Deleting one
Open Presets, then Delete Preset.
Presets are kept on your Mac, in every project.