X and Y like on graph paper. X is longitude, Y is latitude
There is a history why people say latitude/longitude, sadly... you just have to remember which is which.
Esri has them in the correct order for mapping, Google switches them to conform to the way people 'say' and do things. To complicate things, sometimes the negative signs are dropped in favor of a N, S, E, W naming convention. S and W are negative for both
Just make sure you are aware of what you get and how you query