PHP scripts can be embedded in a (X)HTML document or written separately without any (X)HTML markup. In both cases, the file must be saved with the extension .php.
Creating PHP Script:
Any PHP script (code) must be enclosed within the PHP tags which are represented using <?php (opening tag) and ?> (closing tag). Let’s consider a simple PHP script which prints “Hello World” on the web document:
print "Hello World";
Save the above file as hello.php.
Running PHP Script:
To run a PHP script, a web server must be installed and started. Well known web servers are Apache Http Server and Microsoft’s Internet Information Service (IIS).
After a web server is installed, place the PHP file hello.php in the web server’s root directory and start the web server. Now, open a web browser like chrome, firefox or internet explorer and type the following URL in the address bar:
80 is the port at which the web server listens for incoming HTTP requests. The output of the PHP script is:
Watch the below video tutorial for creating and running a PHP script