There are millions of websites that use PHP, some notable ones are Facebook, Digg, Wikipedia and many more.
Nearly all websites have some sort of PHP backend, although a large number use other scripts as well -- Perl, Python, ASP, CGI.
Php
PHP is used for creating web portals, Websites, E-commerce Platform , CMS , ERP Systems, Web Services created in PHP are used in Android Applications.
It supports websites made on php but not coding in php. There are workarounds for coding in PHP using Android.
Primarily it is applied for creating web applications and websites which deal with client-server model. Use mysql db with php and you could build a three tire architecture. Couple of big website like Facebook do use php.
Yes. Many popular websites run PHP on Linux.
PHP is easy and creating attractive and beautiful websites.
Yes, Chrome has PHP module enabled. It can be used for testing and developing PHP websites.
If you are involved in web development you would require to use a server side language. PHP is one of the many server side languages available freely and the coding is not that difficult for php. It is not a iron clad rule that you have to use PHP for web development but the cost of developing and deploying websites using php is less so that is something worth thinking about.
PHP is a programming language. You may be thinking of PCP, or a-PHP (a-Pyrrolidinobutiophenone).
It is used to tell the sever to use the PHP parser. To begin php you must use <?php, and to end it, it is ?>.
You can't use PHP in an HTML document, but you can use HTML in PHP script.