This is a dynamic shared object (DSO) for PHP that will add MySQL database support. The mysqli extension allows you to access the functionality provided by MySQL 4.1 and above. It is an improved version of the older PHP MySQL driver, offering various benefits. The developers of the PHP programming language recommend using MySQLi when dealing with MySQL server versions 4.1.3 and newer (takes advantage of new functionality) More information about the MySQL Database server can be found at https://www.mysql.com/ Documentation for MySQL can be found at https://dev.mysql.com/doc/. Documentation for MySQLi can be found at https://www.php.net/manual/en/mysqli.overview.php.