Php files

Question

whether php files are a good practice to use instead of a database and how to secure it so that only admins can access it. what extensions are used and data written as binary or encrypted

Answer 1

PHP isn't a storage location. It's a backend script that can connect to a database such as an SQL database.

Answer 2

Since it's backend, only the person hosting the website can look at it.

Answer 3

.php is the extension.