Embed blocks allow you to insert third-party content (video, audio, images, tweets, etc.) to your WordPress site. Here are some examples.

This is an example of YouTube embed
This is an example of Twitter embed
https://soundcloud.com/liannajoymusic/adele-hello-cover-by-lianna-joy
This is an example of SoundCloud embed
https://www.instagram.com/p/B7DtqwQAtpp/
This is an example of Instagram embed