How Does PHP Work?

Quick reference

• 00:05 In this video I wanna spend just a couple of minutes talking about PHP, what it is,
• 00:09 how to use it, that sort of thing.
• 00:10 So PHP is what we call a server side scripting language.
• 00:14 And the difference between server side and client side is pretty dramatic.
• 00:19 And it really kind of defines a lot about PHP.
• 00:22 A lot of front-end web developers will use JavaScript or PHP.
• 00:26 Now JavaScript is a client-side development tool, PHP is a server-side.
• 00:30 So what's the difference between that?
• 00:31 Well if you go to any website, let's go to GoSkills.com.
• 00:34 And if you right-click and click the view page source,
• 00:38 you can see the actual HTML and CSS that's used to create this webpage.
• 00:42 And if you look around here on a lot of websites, you can also see,
• 00:46 like right here, this is JavaScript.
• 00:47 And this is right on the page itself, right on the HTML.
• 00:51 And this gets executed right in your web browser.
• 00:53 That's a client-side programming language, it gets executed on the client-side.
• 00:58 PHP is a little bit different.
• 00:59 We actually write PHP code on an HTML page, but
• 01:03 it actually gets executed on the web server back up in the Internet somewhere.
• 01:07 And there's lots of different web servers,
• 01:09 we're not gonna get into that in this video or this course.
• 01:11 But Apache is one of the most popular web servers, PHP runs on Apache,
• 01:15 it runs on every web server, basically.
• 01:17 So that's sort of a distinction to understand, you may not understand exactly
• 01:20 what that means at this point, you'll start to understand that later on.
• 01:23 And in the next couple of videos, we'll show you how to setup PHP and
• 01:27 get in running, so that we can use it on a web server.
• 01:30 But that's sort of an important thing to understand.
• 01:33 Next, I wanna spend just a minute talking about how to actually write PHP code.
• 01:37 And PHP code is a little bit different, and
• 01:39 we'll get into this a little bit later.
• 01:40 But like I said, you write your PHP code right on an HTML page,
• 01:44 right in your HTML document.
• 01:46 And to use PHP on a website, we use these opening and closing brackets.
• 01:52 And it starts with a question mark and PHP, and it ends with the question mark.
• 01:57 So this is a common PHP tag, just like this.
• 02:01 And I've just got a Sublime text editor open right now.
• 02:04 This doesn't really matter, you can use any sort of text editor you want.
• 02:07 And we'll get into that later on, but just for purposes of showing you this.
• 02:10 Anything we write in between these opening and closing tags is gonna be our PHP.
• 02:16 So we could type in echo Hello World,
• 02:21 put a semicolon and this is valid normal PHP.
• 02:26 And like I said this gets executed up on a web server, but
• 02:29 it gets written on your HTML page.
• 02:31 A little bit confusing, but
• 02:32 what happens is when the webpage loads it sees this tag.
• 02:35 It notices, hey this is PHP.
• 02:37 It calls back to the server and executes this thing and
• 02:40 then the server replies with whatever return your code suggests and
• 02:45 then it prints this out onto the screen.
• 02:47 So it may be a little confusing at first as we start to use this it will get
• 02:50 very clear what I'm talking about, but that's the main designation.
• 02:53 The main thing that sets PHP apart from other languages, like JavaScript,
• 02:57 is that PHP gets executed on the web server on the server-side,
• 03:01 as opposed to the clients side.
• 03:03 So in the next video we're gonna talk about setting up a local development
• 03:05 environment on windows.

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