What can PHP do?

At the most basic level, PHP can do anything any other CGI program can do, such as collect form data, generate dynamic page content, or send and receive cookies.

Perhaps the strongest and most significant feature in PHP is its support for a wide range of databases. Writing a database-enabled web page is incredibly simple. The following databases are currently supported:

Adabas DIngresOracle (OCI7 and OCI8)
FilePro (read-only)mSQLSolid
HyperwaveDirect MS-SQLSybase
InformixODBCUnix dbm

PHP also has support for talking to other services using protocols such as IMAP, SNMP, NNTP, POP3, HTTP and countless others. You can also open raw network sockets and interact using other protocols.