HTML is all you need!08/19/2020
Text written to accompany a presentation about HTML on an online meetup
So today I am going to walk you through the very basics of html, how your browser reads and renders it, a little bit of what is an HTTP request and point out where CSS comes in play, but I won't get into much details about CSS.
What is HTML?
HTML stands for hyper text markup language and it is a declarative programming language that is not turing complete.
It was invented in the beginning of the internet to easily exchange written documents across the world wide web (WWW) using http, one of it's most innovative features was that a document could be linked to as many other documents as someone wanted. This is the base of what you today use on your browser.
What is HTTP?
HTTP stands for hyper text transfer protocol, and as the name implies it has strong relations with HTML, at least for when and why it was invented.
HTTP is a transfer protocol built on top of the Transmission Control Protocol(TCP) to reliable transfer files across the WWW enabling hypermedia information systems. In other words, it allows you to click a link and open another page or a cat picture.
Note: HTTP can be adapted to use User Datagram Protocol(UDP)
How the browser interacts with all this?
A Browser is basically a an HTTP client that requests files across the web, in other words it fetchs a file from a server, an HTTP server.
So when you open google.com you request the server responsible for this domain (google.com) the address "/" and as a response google sends you an HTML file that your browser will render!
Note: Right click on browser and look at the page's source code, what you will see is a big HTML file.
Note: Some parts of a page are actually rendered by your operating system(OS) and not by the browser. One example is dropdown menus (
<select>) that will look in one way on your computer and a totally different way on your mobile phone.
What can I write in HTML?
Basically text, a lot of it.
You can also point to other files and your browser will do its best to render it. For example you might want to show an image alongside your beatiful text, so what you do is you write some markup that points to another file (an image) that your browser will make a second request on the background, will get its response and renders it in your page view.
Note that although most of the common browsers will embed the image file into the document, not all browsers are like that or may be configured to not do that. This is the case for browsers like Lynx, a terminal based browser that as far as I know only displays texts.
Some people might configure a browser not to load images to test accessibility, simulate a text browser or they might just not like images.
HTML is written using tags that are written like
<tag></tag>, each tag has its
purpose: add content inside the document, add information about the document or
add semantic structure to the document.
Inside each tag you can declare multiple attributes using the syntax
<div class="button" disabled>New post</div>.
Most of HTML tags needs an opening (
<>) and ending (
</>), but some can be
opened and closed at once:
<input type="text" />.
Here is a nice picture of an "html periodic table" by Castus that I've found on Smashing Magazine
Those are all HTML tags that existed when this table was designed in 2015, nowadays there might be some small differences.
I created some HTML examples that you can find in this editor
Hope you enjoyed, keep coding!