Finite Set
1. The problem is to understand what a finite set is.
2. A set is a collection of distinct objects, called elements.
3. A finite set is a set that contains a countable number of elements.
4. More precisely, a set $S$ is finite if there exists a natural number $n$ such that the number of elements in $S$ is exactly $n$.
5. For example, the set $\{1, 2, 3\}$ is finite because it has exactly 3 elements.
6. In contrast, an infinite set has an uncountable or endless number of elements, like the set of all natural numbers $\mathbb{N} = \{1, 2, 3, \ldots\}$.
7. Therefore, a finite set is one where you can list all elements and count them to a final number.