I recognize this map from a music theory tutorial site with loads of great information: http://mugglinworks.com/chordmaps/chartmaps.htm
Originally I thought I recognized this map from a different large online collection of music theory lessons which are also certainly worth a look: https://www.musictheory.net/lessons
Here you'll find a page that explains the above image in more detail: https://www.musictheory.net/lessons/57
It includes an interactive, step-by-step explanation of progressions, with a virtual keyboard and everything.
With the increasing popularity of music technology and facilitation of home production, I worry that music theory is starting to lose its value amongst musical circles. But it's extremely valuable, and if you aren't particularly versed in theory, this site can do wonders for your understanding.