Question

What are the basic concepts of sets? how many types of sets there are?

Answer 1

We often deal with groups or collection of objects in real life, such a set of books, a group of students, a list of states in a country, a collection of baseball cards, etc. 

Sets may be thought of as a mathematical way to represent collections or groups of objects. The concept of sets is an essential foundation for various other topics in mathematics. 
This series of lessons cover the essential concepts of math set theory - the basic ways of describing sets, use of set notation, finite sets, infinite sets, empty sets, subsets, universal sets, complement of a set, basic set operations including intersection and union of sets, using Venn diagrams and simple applications of sets. 
Empty set
Singleton set
Finite and Infinite set
Union of sets
Intersection of sets
Difference of sets
Subset of a set
Disjoint sets
Equality of two sets