* This excerpt was taken from pages 1-7 of Quick and Fun guide for HTML and CSS by Hamit Peña Sierra.
The web: What is it all about?
The world wide web has become an essential form of communication nowadays, a universal media of endless resources and possibilities.
It can be defined as a global collection of linked documents and resources, which are mostly accessed using a communication protocol named HTTP (Hypertext Transfer Protocol).


To solve it, Tim wrote three fundamental technologies:
HTML: It stands for HyperText Markup Language and is a language used to format documents on the web.
URI: standing for Uniform Resource Identifier. Its a kind of “address” that is unique and is used to identify each resource on the web.
HTTP: which, as mentioned before, stands for Hypertext Transfer Protocol. It’s a sort of communication agreement that allows the sharing of resources from across the net.
These three technologies remain today as the foundation of the web.
Every device connected to the web can play two main roles: they can be either clients or servers.

What is the server’s job?
Web servers are all the time waiting for requests from web browsers. Requests could be made for web pages, images, sounds, or any other resources.


When you click, for example, on a link to visit a page, that click fires a request to a web server for an HTML page, the page is sent to the browser, and then it is displayed in your browser’s window.

HTML is the technology that tells the browser all about the content and structure of the received document and, based on that information, the browser can render the document.
Markup Languages?
When creating regular documents, our primary objective is to let the information be as precise as possible for our intended readers; usually, those readers are going to be human (as the time this book was written, they’re still humans).
However, those documents we write in our language are not going to be understood by computers and not by browsers (they are not that intelligent).

They need documents to be written in a particular language, that explains to them how are they structured, these are commonly known as Markup Language.
A markup language is a system for annotating a document in a way that the computer can manipulate it and understand it. Most markup languages are also human-readable because the annotations are written to be distinguished from the text itself
For example, with HTML, XML, and XHTML, the markup tags are formed by the < and > symbols.
Any text or value that appears within those characters is considered part of the markup language and not part of the text.

In most of the books we read every day, we can see some tags or icons that indicate if the text written in that section is a piece of advice, clarification or just a tip.
In the same way, markup languages tag the elements on their documents so it can be correctly interpreted by a computer.
Some of the most known Markup Languages are:
- XML which stands for Extensible Markup Language and can be used to write or specify other markup languages
- KML – Keyhole Markup Language, which is used to create layers on Geographic Information Systems (GIS) like Google Maps
- HTML – Hypertext Markup Language which is the primary language used on the web
Hello World HTML
Now it’s time to get you into the action, let’s create the first document using HTML; you might not understand every detail just yet but don’t worry about it. It just a first document and you’ll get to know every element shortly.
There exists an ancient ritual we must follow to be able to fully understand every detail in every new learning process…

…maybe we just exaggerated a little, but it is a common practice to start creating a first document or program just saying Hello to the outside world. Let’s do it!
Open a text editor (notepad or any other) and write the following text in a new file.


Now you can add “HTML” to your CV as a skill… Just kidding!
Summary
- The web is a collection of digital resources across the entire world
- HTTP is a communication agreement to share documents on the web
- Markup Languages are used to tag documents to be computer-readable
We must follow the Hello World ritual every time we learn a new technology- HTML is a Markup Language
HTML HTTP Markup Languages Quick and fun guide for HTML and CSS Tim Berners-Lee Web