Fungible, Non-fungible

What's the difference between fungible and non-fungible?

Simply put — fungible means there is no difference in value between two things exchanged between parties (if you have a $1 bill and I have a $1 bill, neither of us lose or gain anything by exchanging them).

Non-fungible means the opposite. I have an original Picasso, you have a finger painting. They are both works of art, but their values are not interchangeable.