If you search for the term “Accessibility” on Wikipedia, you will get the definition as follows:

Accessibility is the design of products, devices, services, vehicles, or environments so as to be usable by people with disabilities. The concept of accessible design and practice of accessible development ensures both "direct access" (i.e. unassisted) and "indirect access", meaning compatibility with a person's assistive technology (for example, computer screen readers).

Let’s scan the elements of this definition in more detail.

Disability

To fully grasp the meaning of “Accessibility”, it is crucial first to understand what the term “Disability” stands for. As defined by The United Nations Convention on the Rights of Persons with Disabilities, disability is

long-term physical, mental, intellectual or sensory impairments which in interaction with various barriers may hinder [a person's] full and effective participation in society on an equal basis with others.

As you can see, it’s not the impairment by itself that is causing the disability to fully participate in society, but rather its interaction with the barriers that are, in most cases, designed by that society. When we are designing our products, devices, services, etc., with able-bodied people in mind, we tend to overlook a big group of people that could also benefit from those products, use them, love them and, in the end, pay for those products and make your business more successful.

Removing barriers for people with disabilities and making their lives easier with your products is the right thing to do. Since your business could only benefit from it, there is no reason not to thrive on making them accessible.

Direct and indirect access

When we think about direct and indirect access in terms of digital products and services, it’s fairly easy to draw the line between them.

Direct access means that your web page/web application/mobile application is accessible and usable with no assistance — it would include things like proper contrast, proper text size, meaningful navigation, clearly written content, no extreme flashing or animation, and similar.

Indirect access would include using those products with additional technology — accessibility settings on your desktop or mobile device or other assistive technologies (you can read more about them in the QA chapter of this Handbook).

To make fully accessible products, it’s important to ensure they are both directly and indirectly accessible.

Design

And last but not least, although this definition focuses on design, in the development of digital products, we need to have a holistic approach. If we want to develop accessible products, accessibility needs to be integrated into each stage of the project lifecycle — starting from design, then through the development phase, and finally, testing against accessibility guidelines and best practices.