How does algebra relate to this chess notation?
Why do they call this chess notation algebraic?
Algebraic notation is quite old. It is based on a system created by Philipp Stamma (c.1705–55) before descriptive notation started to evolve. There is no indication that anyone with a mathematical background had anything to do with its development or spreading, so my best guess is that they called it "algebraic" simply because it uses coordinates. The funny thing is that there is nothing algebraic about coordinates. If anything, it should be called "geometric notation", but somehow "algebraic" sounds better; as if it is more accurate.
In brief, I strongly suspect that they just called it "algebraic".