Plug is one problem...
VOLTAGE and CYCLES are the more important things to note.
most countries around the world use either the 110V / 60 Hz or 220
V / 50 Hz electricity. Not to mention there is at least 4 more 3
phases standard (but this is another story itself)
For domestic usage, there is many variations..... 110 V / 50Hz, 100
V / 60 Hz, 120 V / 60 Hz.
or 210 V / 50Hz, 220 / 50 Hz, 208 / 60hz, 250 / 50 hz.
And not to mention.. some countries were crazy enough to us DC for
their grid.
And some countries changed midway (was 110 V, now 220 V)
