In this Join all the content of both table will come in resultant table either they will be matched or not .
Outer Join are of two types :
1) Left Outer Join -> It is also known as left join . In left join all the content of left table will come in resultant and from the right table only matching rows will come . If no rows is matched from right table then null value will be returned .
Syntax :

select table1.column1 , table2.column2 ..from table1 left join table2 on table1.column_name = table2.column_name ;

Example of left join :
First Table name : Employee_Info

Employee_Id    Employee_name            Employee_Age          Employee _Salary
  1            Mukesh                  23                           100000
  2            Ayush                   24                           200000
  3            Ishan                   20                           400000
  4            Pranav                  35                           700000
  5            Abhishek                26                           800000
  6            Ravi                    25                           300000
  7            David                   40                           800000

Second Table name : student

 
    Student_Id  Student_name            Student_Age          Student_Id
       1        Mukesh                  23                    1
       3        Ayush                   24                    2
       4        Ishan                   20                    4
       16        Pranav                  35                    7
       15        Abhishek                26                    8
       12        Ravi                    25                    3

Now to join these above two tables using left join see below :

select Employee_Id , Employee_name , Student_name from Employee_Info left join student on Employee_Info.Employee_Id = student.Student_Id ; 

Output :All rows from left table and from right only matching column will come

Employee _Id       Employee_name                 Student_name 
        1            Mukesh                          Mukesh
        2            Ayush                           Null
        3            Ishan                           Ayush
        4            Pranav                          Ishan
        5            Abhishek                        Null
        6            Ravi                            Null   

continue for right join in next blog .............