Web Standard - World Wide Web Consortium (W3C)

Before to learn the Web design, usability, accessibility, etc. I think we should know there is a web standard - World Wide Web Consortium (W3C).
W3C is an organizations which creat Web standards and guidelines.
Their mission is :

To lead the World Wide Web to its full potential by developing protocols and guidelines that ensure long-term growth for the Web.

If there are not stardard to contorl the web protocol, it will be a messy world in the internet. So, W3C want to achieve the goal of one Web, which is specifications for the Web's formats and protocols must be compatible with one another. Also it should allow (any) hardware and software used to access the Web to work together.

The Web is an application built on top of the Internet W3C contain lots of key information and terms of the web.
It contain a w3C Search, site index and keywords for the user to search what they want to explore or reference to. It contain some guildline or the protocol standard. The site index will help you to find the topic easy and quickly.

For me, i am fresh in the web design. W3C School really help me to learn the programming language of web.
It contains HTML, CSS, XML, JavaScript, ASP, PHP, SQL ...etc
Every topics will contain lots of tutorials for us to learn with.
Besides the tutorial, it contain the quiz test for self-evaluation.
We can learn the programming language from the web.

Another powerful function is about the VALIDATION.
As W3C is the web standard, after develop the web site. we can post the web page to related protocol validaton. It will indicate the wrong code of that page.

I think this web site really help us to become a professional Web developer!