SQL Cross means cartesian product of the rows of two or more tables . It return all the rows of the table when each row of the first table combined with the each row of the second table . It is also known as cartesian or cross join .
Cross Join can be represent by two ways :
1) Using Join Syntax .
2) from clause without using a where clause .

Syntax :

select * from table1 cross join table2  ;
or
select * from table1 , table2 ;

Example of Cross join :
First Table name : Employee_Info

Employee_Id    Employee_name            Employee_Age         
  1            Mukesh                      23                      
  2            Ayush                       24                   

Second Table name : student

    Student_name            Student_Age        
      Abhishek                26                    
      Ravi                    25                    

Query for Cross Join :

select * from Employee_Info cross join student ;

Output :

Employee_Id      Employee_name      Employee_Age      Student_name      Student_Age
     1            Mukesh                 23             Abhishek            26      
     2            Ayush                  24             Abhishek            26    
     1            Mukesh                 23             Ravi                25      
     2            Ayush                  24             Ravi                25