An asset, simply put, is something that puts money into your pocket. A liability is something that takes money out of your pocket.
Common thinking is that you should save up for a house, as it is an asset. However, all a house seems to do is take money out of our pockets: tax, gas, insurance, maintenance and more.
Robert Kiyosaki suggests that actually, the personal home is just one big liability. Some good food for thought.