Flight Mode?

Does anyone know what the flight mode means/does? When I try to access my network at home via wifi and the icon with the two opposing arrows on the top of the screen is pressed it has a highlighted option of turn flight mode on or off. What is this and what effect does it have on my access to my network? Thanks.

[G22]

Prob something to do with being in an airplane. You need to turn the wireless off if not mistaken.

Lufthansa now has wifi on some of their aircraft. Maybe, maybe not.

http://www.phonescoop.com/glossary/term.php?gid=148