Vision: A new user should be able to clearly differentiate between Driver, Extension and Library for MongoDB.

Problem: There is an inconsistency in the terminology we use around PHP Driver and extension. Sometimes the "PHP Driver" refers to the PHP extension, sometimes to the combo MongoDB Extension + PHP Library. This can cause confusion to the new users.

Examples

1. The MongoDB PHP Driver consists of the two following components - https://www.mongodb.com/docs/drivers/php/#introduction 
2. The page is titled MongoDB driver though it’s referring to the extension - https://www.php.net/mongodb
3. The MongoDB PHP Library provides a high-level abstraction around the lower-level PHP driver, also known as the mongodb extension. - https://www.mongodb.com/docs/php-library/current/ 

Expected

We should standardize the terminology/naming scheme across our documentation.