PHP is the world most popular backend programming language for the web development which is widely using by 82.5% of the websites. The world top internet based companies like- Facebook, Twitter, Baidu and Wikipedia are using PHP at the server side. There are many benefits to using PHP over any other programming language:-
We have a busy life. If a website takes more than 5 seconds to load than 70% of the visitors left it. If you planning for a news website or a technical blog than load time must be less than 3 seconds and the PHP has the ability to perform backend tasks in minimum time.
All the tools and software require to develop the PHP are completely free. It simply means you don't even need to invest a single penny.
Since LAMP is open source, there are a number of community members who are working to make PHP more secure and reliable.
We can run PHP at any platform including Linux, Unix, Windows and Mac.
If we need to make a simple web application than PHP is much faster over asp.net. However, in few cases where the application is really complex like executing 2 million loops than asp.net can be preferred over PHP but most of the websites don't need to do that.
It takes a lot of time to setup and deploys the asp.net application in comparison of PHP. Even a beginner can setup LAMP within 5 minutes.
PHP have a larger community where a programmer can get the support easily. If community is larger then more peoples are building the useful tools which can be used directly in the applications. It's third largest community at the stackoverflow communities.
The World most popular frameworks including Laravel, Symfony, CodeIgniter, Zend Framework and Phalcon has developed using PHP. The most popular content management system Wordpress is using PHP and MYSQL in the backend which powers to the 27.5% websites of the world.