What are the main differences between a Girlfriend and a Wife?

Both girlfriend and wife are relationships between men and women or ladies and gentlemen. Both relationships have their merits and demerits in their defined sphere. One of the basic/primary difference is that a girlfriend can become wife and the reverse is a taboo in many cultures across the globe. Also, when you fallout with your girlfriend, she picks up her stuff and go to her home while the wife will remain in the same house with you; both of you ended up sleeping in the bed. Therefore, a wife and a husband is a relationship where two temporary enemies end up sleeping in the same bed facing the walls. Some individual will say wife is an investment, opinion varies. My dad told me and my brothers long ago that a wife is a bank while a girlfriend is a post office. Your thoughts? Welcome to provocativedbate.com.