Web accessibility is crucial for ensuring that everyone, including people with disabilities, can access and use websites on the internet. The Web Accessibility Directive in Europe requires public sector websites and mobile apps to meet WCAG 2.1 AA, but it is also relevant for private organizations. By designing websites with accessibility in mind, we can create a more inclusive and equitable online environment that benefits all users. This article covers various aspects of web accessibility, including the legal and ethical implications, quantifying the demand, semantic web design, screen readers, keyboard accessibility, cognitive accessibility, project management and architectural concerns.