Okay, I finally got my head around the nodes. I didn’t find the Wikipedia pages as much help since they are extremely comprehensive.
But for anyone else: from what I gathered, the Dot, node compares the similarities between two vectors on a range from -1 to 1. Specifically as normal directions.
Then the ASINd converts them to degrees. But, for my case anyway, Dot was all I required to get the results I needed.