Using ext/mysqli: Part I - Overview and Prepared Statements
http://www.zend.com/php5/articles/php5-mysqli.php
The major features of the extension are:
- A procedural interface that looks very much like the ext/mysql interface
- An object-oriented interface that allows for a use idiom that is both more convenient and easier to extend than the procedural interface
- Support for the new MySQL binary protocol that was introduced in MySQL 4.1. (The new protocol is more efficient that the old one and allows for the support of a broader range of features, such as prepared statements.)
- Support for the full feature set of the MySQL C client library, including the ability to set advanced connection options via mysqli_init() and related functions.
Additionally, the extension has support for additional tracing, debugging, load balancing and replication functionality.