PHP can run on both Unix and Windows servers, which makes it more accessible than its Windows counterpart, Active Server Pages (ASP). Most full-service web design firms will have at least one PHP guru.
PHP uses are widespread, and can include any kind of server functionality that takes user's input and displays or manipulates the input. Some pertinent examples of such work are message boards, auction sites, shopping carts, and more. There are numerous free (open-source) scripts out there for PHP newbies to use. This synopsis is meant to serve only as a gateway to other works; although the main goal is to give a reader enough information so they can make educated decisions about what their web developer should do. For those looking to get into PHP, there are many free tutorials and primers out there: http://www.4webhelp.net/tutorials/php/basics.php is a pertinent example.
PHP generally uses the mySQL database system. MySQL is a server-side system that is included on many Unix, and some Windows servers.
On the other hand, Active Server Pages runs – for the most part – solely on Windows servers. This can cause some problems. Windows hosting or private servers generally cost more than Unix servers, making it less accessible than PHP. Like PHP, ASP can do just about anything. There are considerably fewer open-source scripts written in ASP, another testament to its inaccessibility. For those interested in ASP, here's a great free tutorial: http://www.w3schools.com/asp/default.asp .
ASP can use many different database systems. Many users prefer Microsoft Access. Access, unlike MySQL, offers a what-you-see-is-what-you-get (WYSIWYG) editor as part of Microsoft's Office suite. In fact, you may already have a copy of Microsoft Access on your computer and not even know it. Its uses aren't limited to databasing, it's also used as a basic spreadsheet application for those who need a more programmer-friendly environment than Excel. ASP can also work well with MSSQL or MySQL.
It's difficult to say which of the three programming languages, or the numerous others for that matter, is the best. There will always be disputes, and no standard is set. With the varying interpretations of what a programming language should be, predilections to PHP or ASP arise. PHP is certainly more widely used, but isn't necessarily the best. When a site is being created to be interactive, a professional can give an educated opinion on which technology should be used