Intro to The Web

The Web, or internet, or interwebs, is possibly the most impactful thing to be introduced to human culture in the last 20 years. It anyone with a computer access to the sum of human knowledge. The Web is dominated by open source hardware and software solutions, far too many to count. We'll be experimenting in depth with various web-based languages, techniques, and concepts, but first, let's start at the beginning. How does the Web work?

Domain names are a good place to start because they are the identification of servers, which host the files that make up a website. The domain is the "name" of the website. The beginning of the domain name represents the protocol, such as http://, which means the domain is responding with HyperText Tranfer Protocol. Any computer running webserver software on it can host files to other computers.

Domain names are registered on Domain Name Servers, which link the domain name to the IP address of the computer hosting the website.

Anyone can register a domain name for a monthly fee. There are a number of ways to register a domain name, but it's useful to know if it's been registered or not. There is a WHOIS document attached to every domain, which lists the registrar of the domain, that is, who registered it, the admin contact, and other information.

AjaxDomainSearch is open source and releases their code freely, and you can download it.

Some others:
http://instantdomainsearch.com/
http://ajaxwhois.com/

HTML - A Markeup Language

We'll start by experimenting with HTML, which is a Markup Language used to describe Web Pages, created in 1991. HTML is not a programming language like Processing or JAVA that we've been working on in this course. It literally is text that is marked up with "tags", and read by the web browser in a top-down fashion. HTML tags are interpreted into Elements, resulting in the visual building blocks of all websites. There is no embedded logic, variables, or functionality in HTML. HTML tags simply wrap around text. Certain HTML elements, such as the <script> tag, <canvas> and <embed> allow you to write code into HTML documents with other languages -- most commonly Javascript. Flash, and other media are plugins, which rely on the <embed> and <object> tags.

So, your web browser reads HTML documents and displays them as web pages. The browser interprets the HTML tags as page elements.

Who Comes Up with the HTML Tags?

The Word Wide Web Consortium (W3C) is a standards organization that oversees HTML tags which are contributed by the community. There are web standards that follow a set of guidelines and best practices, overseen by the W3C. They also maintain the official Markup Validator, which you can run a website through to see if it's written to the HTML specification.

Writing HTML

There are two types of HTML tags. Let's use the <strong> tag as an example. The code:

<strong>This text will be bold.</strong>
displays as:
This text will be bold.

The <br> tag is a single tag format (a line break), for example:

some text <br /> text <br /> text
displays as:
some text
text
text

The <br /> tag does not have an ending tag, so we have the backslash "/" before the ending bracket.

Tags can have attributes, such as:

<img src="some/image.jpg" /> 

Where the "src" attribute points to the location of the image. Tags can have multiple attributes, for example:

<div style="background:rgb(0,0,0);" id="element1" /> 

which gives this div a background of black via its "style" attribute, and the id "element1" via its "id" attribute.

References

HTML Tag Reference
W3C Markup Validator
Ajax Domain Search
HTML
Domain Names
Domain Name Systems
IP Address
W3C