SQL insert statement is used to insert the data in a table in database . Using this statement we can insert single or multiple data in a table .
We can insert the data by two ways :
1) By SQL insert into statement : we can insert data either by column name or without column name .
2) By SQL select statement

1) By SQL insert into statement : If you don't want to use select statement to insert the data then you can insert directly , example given below .
Syntax :

insert into table_name ( col_name1 ,  col_name2 ,  col_name3 , ............... col_nameN) values ( value1 , value2 , value3 , ..................valueN) ;

Example :

insert into Employee_Info ( Employee_name , Employee_Age , Employee _Salary )  values ( Mukesh , 23 , 100000 );
insert into Employee_Info ( Employee_name , Employee_Age , Employee _Salary )  values ( Ayush , 24 , 200000 );
insert into Employee_Info ( Employee_name , Employee_Age , Employee _Salary )  values ( Ishan , 20 , 400000 );
insert into Employee_Info ( Employee_name , Employee_Age , Employee _Salary )  values ( Pranav , 35 , 700000 );
insert into Employee_Info ( Employee_name , Employee_Age , Employee _Salary )  values ( Abhishek , 26 , 800000 );
insert into Employee_Info ( Employee_name , Employee_Age , Employee _Salary )  values ( Ravi , 25 , 300000 );
insert into Employee_Info ( Employee_name , Employee_Age , Employee _Salary )  values ( David , 40 , 800000 );

Table name : Employee_Info

 Employee_name            Employee_Age          Employee _Salary
      Mukesh                  23                           100000
      Ayush                   24                           200000
      Ishan                   20                           400000
      Pranav                  35                           700000
      Abhishek                26                           800000
      Ravi                    25                           300000
      David                   40                           800000

If you ignore the column name , then It will also work like :
Syntax :

insert into table_name values ( value1 , value2 , value3 , ..................valueN ) ;

Example :

It will also generate same result ;

 insert into Employee_Info  values ( Mukesh , 23 , 100000 );
    insert into Employee_Info  values ( Ayush , 24 , 200000 );
    insert into Employee_Info   values ( Ishan , 20 , 400000 );
    insert into Employee_Info  values ( Pranav , 35 , 700000 );
    insert into Employee_Info  values ( Abhishek , 26 , 800000 );
    insert into Employee_Info  values ( Ravi , 25 , 300000 );
    insert into Employee_Info values ( David , 40 , 800000 );

2) By SQL select statement

  insert into table_name ( col_name1 ,  col_name2 ,  col_name3 , ............... col_nameN) values select  col_name1 ,  col_name2 ,  col_name3 , ............... col_nameN from table_name where clause ;

If you want to add a new row then you can also add , but remember , that column name should be matched with that data type .