Question on the ''m2''

ok im growing 11 plants, in a 4x6 flood tray, 6 og kush, 3 strawberry blue, and 2 cheesexhaze, now my question is this, on the packets it says, for example

OG kush (yield indoors 350-400m2)
Strawberry BLue(500-600m2)


what exactly is m2, sorry if this is a dumb question but i couldnt seem to figure this out by myself, thanks to those who actually respond and help.

m2 = Meter squared (3 ft x 3 ft area)