PHP is a general-purpose scripting language that is especially suited to server-side web development, in which case PHP generally runs on a web server. Any PHP code in a requested file is executed by the PHP runtime, usually to create dynamic web page content or dynamic images used on websites or elsewhere. It is a widely-used open source general-purpose scripting language that is especially suited for web development and can be embedded into HTML.
Performance: Script written in PHP executes much faster than those scripts written in other languages such as JSP & ASP.
Open Source Software: PHP source code is freely available on the web, you can develop all the version of PHP according to your requirement without paying any cost.
Platform Independent: PHP is available for WINDOWS, MAC, LINUX & UNIX operating system. A PHP application developed in one OS can be easily executed in other OS also.
Compatibility: PHP is compatible with almost all local servers used today like Apache, IIS etc.
Embedded: PHP code can be easily embedded within HTML tags and script.
Easy to learn: PHP is easy to learn and use. For beginner programmers who just started out in web development, PHP is often considered as the best and preferable choice of scripting language to learn.
Open source: PHP is an open-source project -- the language is developed and maintained by a worldwide community of developers who make its source code freely available to download and use. There are no costs associated with using PHP for individual or commercial projects, including future updates.
Portability: PHP runs on various platforms such as Microsoft Windows, Linux, Mac OS, etc. and it is compatible with almost all servers used today such Apache, IIS, etc.
Fast Performance: Scripts written in PHP usually execute faster than those written in other scripting languages like ASP.NET or JSP.
Vast Community: Since PHP is supported by the worldwide community, finding help or documentation for PHP online is extremely easy.