Key Concerns of Accessible Web Applications

It's best to focus on the following three areas when making a web application accessible:

• Semantic Markup - Allows the application to be understood on a more general level rather than just details of whats being rendered
• Keyboard Accessibility - Applications must still be usable when using only a keyboard
• Visual Assistance - color contrast, focus of elements and text representations of audio and events

原文: https://angular-2-training-book.rangle.io/handout/a11y/key-concerns/