What is PHP?
PHP stands for PHP Hypertext Preprocessor. PHP is a powerful and widely-used open source server-side scripting language to write dynamically generated web pages. PHP scripts are executed on the server and the result is sent to the browser as plain HTML.
PHP can be integrated with the number of popular databases, including MySQL and other. PHP can be embedded within a normal HTML web pages. That means inside your HTML documents you'll have PHP statements like this:
<html> <head> <title>PHP Application</title> </head> <body> // Display greeting message echo 'Hello World!'; </body> </html>
What You Can Do with PHP?
You can generate dynamic pages and files. You can create, open, read, write and close files on the server. You can collect data from a web form such as user information, email, credit card information and much more. You can send emails to the users of your website.
You can send and receive cookies to track the visitor of your website. You can store, delete, and modify information in your database. You can restrict unauthorized access to your website. You can encrypt data for safe transmission over internet.
Installing and starting PHP
Installing PHP is pretty straightforward. First, we need to install PHP on our device.
You can see how to do this in this video. It will show you how to download PHP on a Windows and on a Mac machine.
All these are excellent editors. It's just a matter of personal preference. I would say just pick up one that you like and stick with it.