Set

A set is a list that is:

• Unordered
• No quantities

Therefore:

• We cannot get a specific item of a set based on a number (e.g. cannot get x card)
• Cannot have quantities

To illustrate these these is all equal to $\{1,3,5,7\}$:

• $\{1,1,1,3,5,7\}$
• $\{7,3,1,5\}$