What the fuck is PHP?
First thing you gotta know about PHP is its amazing and shitty all at the same time. Like a gas-station burrito at 2a.m.
PHP is one of the original godfathers of web programming. Sure, there was shit before it, but this is where it kinda really kicked off. PHP is a language that programmers use to program the logic of websites on the server. It helped popularize interactivity like sessions and guest books (remember guest books? No? You don’t know what you’re missing out on…)
PHP stands for Personal Home Page. It started out as a way to make things easier to program, so it wasn’t really feature-filled and planned. This lead to some really shitty ways of doing things (and hence why sometimes you’ll hear programmers turn their nose up and hate on PHP.) It’s progressed since it was created in 1994, though. Many enterprises have used PHP (or flavors of it) including Yahoo and Facebook.
Also Wordpress, which is about 30% of the internet, is written in PHP. Popular PHP frameworks (pre-made shit to make shit easier/faster) include (but are not limited to) Laravel and Symfony.
PHP is also known as Open Source. This means that anyone can see how the language was created and look through the source code. It also tends to mean that programming done in PHP becomes open source itself (but not always).
PHP programmers are sometimes referred to as back-end programmers. This just means that they tend to deal with business processes and databases more on the server instead of in your browser.
PHP is part of the LAMP Stack.