The advantages of website compliance
Website compliance guarantees the validity of a website code, thus respecting some technical contexts and helping viewing on any browser, operating system and devices (these contexts are closely related to responsive design). In this way, a higher quality web accessibility is guaranteed. In the future, compliance with web standards could be relevant for SEO.
Every professional web designer should ensure compliance with web standards. A standards-compliant website will endure time, when new browsers and new devices will come out. The code that respects the web standards, which requires that the contents are separated from the graphics, allows to save money for any changes to the website. Its structure remains the same, but through specific markup and formatting languages it is possible modify the graphic presentation according to your needs.
The early (chaotic) years of the web
Before the W3C was founded it was common to create websites that worked only on one of the 2 browsers used in those years: Internet Explorer and Netscape Navigator. Although in the following years these and other browsers were involved in the drafting of the web standards, the latter were not properly respected, effectively frustrating the effort of the W3C.
W3C - the consortium for web standards
In October 1994 the W3C was founded, the consortium that laid the foundations for web standards, through rules and technologies. Among its objectives are the maintenance of internet freedom and easier and more direct access to the web for any type of user and with any device. The W3C pays more and more attention to languages and methodologies. But basically are developers who make the web possible as we know it today, effectively anticipating times that would be unthinkable as intended by the W3C.
The latter provides code validators who certify the compliance of all types of websites. Internet can now exploit its full potential through markup, presentation and programming languages, that are taken as a reference by browser manufacturers for the benefit of the end user.