What the different about <input> + <datalist> and <select> tag? Sorry for bad English..

Answer 1

datalist are suggestions that would appear when you'd fill the input that is attached to while select contains specific, pre-set values. In the former, the user can fill the input with whatever he wants whereas in the latter, he/she can only chose one among the options that youve proposed to him/her. This way, the select permits you to limit and control the received values.The interface differs between the two as well.
(bear in mind that although it's not appearent​, any sneaky user can change the select option values easily, therefore, concider do some checkings in the server side)

Answer 2

With <datalist>, you can type inside the input field, and the values in the dropdown are restricted as you type more characters. With <select>, you only have the dropdown.

Answer 3

OK, I got it. I can write other option with <input> + <datalist>. Thank's a lot for all.