Theory:

Let us recall the definition of sets.
A set is a collection of the well-defined object.
Set notation: A set is denoted by capital letters English alphabets \(A, B, C, D,...\)
 
Elements: Elements of the sets are denoted by small letters English alphabets \(a, b, c,...\)
Also, the elements of the set should be written inside the curly brackets .
Types of sets.
There are many types of sets in set theory. They are:
  1. Empty set
  2. Singleton set
  3. Finite set
  4. Infinite set
  5. Equivalent sets
  6. Equal sets
  7. Subsets
  8. Proper set
  9. Power set