mysqli_ ..type functions ??

[PHPycho]

Hello forums!!
I am eagerous to know the use of mysqli_ like functions for mysql operations.
1> whats the difference between mysql_ and mysqli_ type functions ?
2> which one to use and why ?
3> in some code i found a complex queries operations like
mysqli_prepare()
mysqli_stmt_bind_param()
mysqli_stmt_execute()
mysqli_stmt_bind_result()
functions found basically in OO approach, whats its advance over general mysqli_query(),mysqli_fetch_array() ?
4> which type of function is suitable for mysql operations in php5 in relative to performance ?

Can anybody ******** about the facts mentioned above ? It would really greatful for me if i know the answer.

Thanks in advance to all of you

[flann]

here's an explanation of mysqli http://us2.php.net/manual/en/ref.mysqli.php

However, if you're going to learn about a new way to work with databases, I would suggest learning PDO. http://us2.php.net/pdo