If you were stuck on Google’s homepage today trying to understand what the doodle is about, here’s the meaning of each combination. In each case, the “x” and “y” circles of the lowercase “g” letter are hidden or shown according to the highlighted operation as if you were do a search on two terms (“x” and “y”). It goes like this:
G: x AND y = show results with both “x” and “y” (show both are shown)
o: x XOR y = XOR stands for exclusive-or which means that either you find “x”, or “y”, but never both together. So only “y” is shown (technically, showing only “x” would be correct as well – you can blame the limitations of animated GIFs on this)
o: x OR y = shows results with either “x” or “y” is found, so both are displayed
l: NOT y = anything that doesn’t contain “y”, so only “x” is shown
e: NOT x = anything that doesn’t contain “x”, so only “y” is shown
As for who is responsible for all this (text by David Amerland):
Two hundred years ago the English mathematician George Boole came to the world. Boole was to contribute a significant frame of thought to mathematics with algebraic equations that can be used to denote truth values to variables. Boolean logic became to fundamental core of search until semantic search came along with Google’s recoding of its search engine in 2012 and the employment of fuzzy logic based upon the value of relational connections of data points.
Google’s doodle is found here.