Hi! I'm Hello Kitty and I am going to take you on an adventure through economics!

Hello Kitty eats apple pie to survive. It is necessary and is a need.

Hello Kitty wants to eat a cookie. She does not need it to survive, therefore it is a want.

Hello Kitty's parents tells her to only choose one. She has to decide on the better option in terms of price and needs & wants. This is an opportunity cost.

Hello Kitty, you can only choose one.

Hello Kitty was devastated that she had to choose between the two. However she had to pick the apple pie as it is the most responsible decision. This is called a trade off.

One day, Hello Kitty arrived at the restaurant awaiting to be served her apple pies. The waiter informs her that there were no more apple pies due to the lack of apples. This is called scarcity.