PHP :- : Hypertext Preprocessor. It is a server-side scripting language often written in an HTML context. Unlike an ordinary HTML page, a PHP script is not sent directly to a client by the server; instead, it is parsed by the PHP engine. HTML elements in the script are left alone, but PHP code is interpreted and executed. PHP code in a script can query databases, create images, read and write files, talk to remote servers—the possibilities are endless. The output from PHP code is combined with the HTML in the script and the result sent to the user.

PHP 5 introduces numerous new features

·       PHP has new integrated for support for XML. The various functions and classes provided to handle XML in different ways all now use the same underlying library (libxml2). This should make XML features more stable and interoperable.

·       The SQLite SQL library is now bundled with PHP, together with all the functions you need to work with it.

·       PHP now supports private and protected methods and properties in classes.

·       PHP supports class constants.

·       Objects passed to functions and methods are now passed by reference. That is, a reference to an object is passed around your script rather than copies of objects. This significantly reduces the likelihood of bugs in object-oriented code.

·       PHP supports static methods and properties, making more advanced object-oriented designs possible.

·       Methods can now be declared to require particular object types.

·       The comparison operator (===) now checks that two references point to the same object. Previously, it was hard to test objects in this way.

·       PHP now supports abstract classes and interfaces.