Embedding is capturing the developer code to a resource and then adding it to your code so you don't have to download/upload the resource when you embed. An example is when someone uploads a video to YouTube, they automatically grant permission to embed their video.
Adapting would be to change the resource to customize it for your needs, adjust the code for size, add a frame, or make other changes to the resource from the original source.
(Credit given to Holly Stevens for this explanation in Teams from 1.25.2022.)