Define/explain CSS specificity
CSS specificity is the formula used to decide which CSS declaration is applied to an element when there is more than one declaration competing. For example, IDs usually will be applied over a class since they have more weight. However, classes have more weight than a type. There are some exceptions in this formula though and the main one is the !important property. When that property is applied in a class, it will apply the changes even if there is a declaration with more weight.
Define/explain contrast ratios
Contrast ratios are how light or dark colors appear on a screen. This is important to check when testing a website to make sure that the text, buttons, images, etc. show up well on the background color. There is a developer tool in Google Chrome that can easily check the contrast ratio.
Explain why contrast ratios must be met
Contrast ratios must be met for ADA compliance. If a company's website is not ADA compliant, the company could be sued. It is important to monitor a website's ADA compliance status regularly.
Explain what group at the W3C sets accessibility rules
The Web Accessibility Initiative (WAI) sets the accessibility rules at W3C. This group (like the WordPress theme reviewer group) invites people to participate to review guidelines and work on projects.
Summary
Overall, ADA compliance is very important for any website. No one wants to be sued and it's best if a website is accessible to everyone. The developer tool for the contrast ratio in Google Chrome was new to me and I'm looking forward to using it more in the future at work.