All website functionality must be usable by keyboard. This means, among other things, that all links and form fields must be accessible by tab key and usable with the enter key.
When you make efforts to produce accessible websites and apps, you are encouraged to communicate about it. This can be done by publishing an accessibility statement.
Images can be made accessible by either marking them as decorative or by providing an alternative text. Which technique to choose depends on the way the image has been implemented.
Techniques for an accessible disclosure: change the button label to indicate the action, use details with summary or indicate the state with aria-expanded.
CSS allows to insert text, images and icon fonts into a web page. What are the accessibility implications?
A high colour contrast ratio between a text and its background makes said text easier to read for colour blind and partially sighted users.
These attributes are used to give an element it's accessible name. They do the same thing but in different ways.
There are humane, technical, financial, and legal arguments in favour of building accessible websites and applications.
When navigating from link to link by tab key, a user must always be able to see which element receives focus. Define a clearly visible :focus state in your style sheet to achieve this.