French AZERTY on Windows and on Mac have quite some differences in symbol locations, also drives me crazy when switching to my mechanical keyboard.

In AZERTY, the number row works differently. Unshifted gives symbols and commonly-used accented letters like "é" and "à", hold Shift to get a number.

In Windows keyboard, the unshifted "number 8" key corresponds to a "_" while it's a "!" in Mac. The key below Esc on Windows is literally just the superscript 2 for some reason, on Mac it's "@" unshifted, "#" shifted. We also have a key for "μ" and for "§" in Windows.