Could anyone ELI5 this blueprint diagram? Would be much appreciated

The blueprint is from another thread on aligning a character to a surface

Blueprint in question

From what I understand an impact normal is an orthogonal vector from the hit vector? I don’t understand what the make rot from xy function does. What is this rotation relative to? If some unreal forum saint could draw diagrams of what’s happening, that would be amazing, but i’ll take any help I can get in understanding this.

Thank you!