A mathematical sequence found/invented by Leonardo Fibonacci. It makes sense that the Apple logo would be designed after a mathematical principal.
It's basically a bunch of numbers that add up.
0, 1, 1, 2, 3, 5, 8, 13, 21, 34
0+1=1
1+1=2
1+2=3
2+3=5
5+3=8
And so on.
When squared, it makes a "spiral". The circles seen in Grummer's post are in the squares, and the formation of the squares is the "spiral". The people who made that image with the circles over the Apple logo simply applied the sequence to show how the Apple logo was based on the Fibonacci Sequence.