Sql question marks in insert statement

Question

This may seem like a very rudimentary question, but I do not understand. In my code I have a request

    "insert into CONTACTS (EMAIL, FIRSTNAME, LASTNAME, TELEPHONE) values (?, ?, ?, ?)"

What '?' in values, is it a choice of real-time values?

Answer 1

This comes from a trained operator . These question marks will be filled with values ​​later before the request is completed.

Answer 2

In a programming context, where you need to insert multiple datasets into one table -

, , . insert , . '?' , . .

, , . .

SQL- PHP?, , sql, "?".