PHP
(recursive acronym for "PHP: Hypertext Preprocessor") is a server-side,
HTML-embedded, cross-platform and Open Source general-purpose scripting
language. PHP is mainly suited for modern dynamic website development
that demands tailored content based on user’s preferences.
PHP
generally runs on a web server, often used together with Apache (web
server), taking PHP code as its input and creating Web pages as output.
However, it can also be used for command-line scripting and client-side
GUI applications. It also supports ISAPI and can be used with
Microsoft's IIS on Windows. PHP supports a large number of databases
natively and many others are accessible through PHP's ODBC functions.
What distinguishes PHP from something like client-side JavaScript is
that the code is executed on the server. When the php script is
executed on your server, the client would receive the results of
running that script, with no way of determining what the underlying
code may be. Moreover, its syntax is similar to C, Perl and Java.PHP’s
promiscuous-linking to PDF, SWF, XML and Java is another advantage.