This gave me a great excuse to visit every once in a while. German beer is good, Munich beer is divine. Although I could spend hours espousing the popular Pilseners, not to mention the stories resulting from said Pilseners, I'm going to concentrate on the Hefeweizens. Beer is made from malt, generally barley malt. On the other end of the scale, you can use wheat.
Wheat tends to be a little more difficult to brew with, as it has no husk, like barley does.
Hence, it is almost always used in conjunction with barley, for manageability purposes. Beer brewed with wheat tends to be much lighter in color that ales brewed with barley. To the uninitiated this is far more confusion than one can reasonably be expected to deal with, resulting in an intensified desire to just drink the beer, sending the confusion the way of the liver. Sometimes, it isn't enough to use different grains. Hefe is German for yeast.