Hi Karthik,

1. WCAG stands for Web Content Accessibility Guidelines. These guidelines are produced by the Web Accessibility Initiative (WAI) of the World Wide Web Consortium (W3C). Think of WCAG more as web accessibility standards that are commonly referenced vs. compliance (compliance indicates something that is required).
2. In my article above, I reference compliance specifically in regards to the Americans with Disabilities Act (ADA). Broadly, the current legal landscape in the U.S. is that you need to make your website accessible in order for it to be in compliance with Title III of the ADA. WCAG 2.0 is a version of WCAG that is used as a guiding reference by courts but it is not the law in the U.S. Ideally, websites will meet all 38 success criteria of WCAG 2.0 but, practically speaking, this can be extremely difficult to accomplish as some of the language is nebulous and it can be difficult to pinpoint whether your website meets certain success criteria. To answer your question, WCAG 2.0 is a web standard to strive to meet. As a side note, I am currently working on establishing new standards as WCAG was never written to be law but as a technical standards guide.
3. I recommend all websites include an accessibility policy once website owners have taken good faith efforts towards making their website accessible. (It would be hollow to have an accessibility policy but not actually have a policy in place or taken measures to become accessible.)
4. These are all distinct from one another. ADA Website Compliance refers to making your website compliant with the Americans with Disability Act. Section 508 is an amendment to the Rehabilitation Act that requires federal departments and agencies to make their websites (and other “electronic and information technology”) accessible to persons with disabilities. Section 508 has been revised to incorporate WCAG 2.0. The ADA and Section 508 are both law in the United States. The Web Content Accessibility Guidelines (WCAG) are guidelines created by the World Wide Web Consortium (W3C) to establish web accessibility standards to help with uniformity in making websites accessible. WCAG is not the law unless it has been formally adopted by a government. Rather, it is a set of web standards (along with many other types of web standards) produced by an international community who seeks to further the web.