What is the difference between 'accessibility' and 'usability'?

The distinction between accessibility and usability centers around the target audience and purpose of each concept. Accessibility specifically refers to the design of products, devices, services, or environments that are usable by people with disabilities. This includes a wide range of impairments such as visual, auditory, motor, and cognitive disabilities. The goal of accessibility is to ensure that these individuals can fully engage with and benefit from digital content, applications, and services just like anyone else.

By contrast, usability is a broader concept that pertains to how effectively, efficiently, and satisfactorily a user can interact with a product or service. While usability is certainly a crucial aspect of web design, it is not exclusively focused on individuals with disabilities. It applies to all users, aiming to create intuitive and pleasant user experiences regardless of their abilities or the devices they use.

Understanding this distinction is vital in web development and design, as it emphasizes the importance of creating inclusive environments that cater not only to general usability but also to the specific needs of users with disabilities.