Nowadays, money is all in life, although we usually say health is the main, it isn't really true. All we and all depend on money.
When I go shopping, I carry cash because I can't carry a credit card because I'm not 18 years old yet. Most people carry their credit card, and I reckon it's more comfortable than carrying cash. On the contrary, people still carry cash when they go shopping.
Now they are developing a new way to pay using your own mobile phone. I would try to pay with mine, it must be exciting. In my opinion, it is more comfortable than paying with cash, even, than paying with a credit card. This reminds me of the advertisement where an elderly man who is on a scooter pays for something with his mobile.
Mark Zuckerberg is the co-founder and CEO (Chief Executive Officer) of the networking website Facebook. He is also one of the world's youngest billionaires. He has such an enormous quantity of money! He has $47.1 billions.