In this video, Dylan Rambow of Northern Illinois University talks about global fields, in particular what types of fields qualify as "global" and why we bother to define such a collection of fields, and how to construct the adele ring of a global field.
This video is the third in a series on algebraic number theory. Here are the first two:
https://youtu.be/XCTpvETc6UA
https://youtu.be/DhPYLiuIuLI