Usability measures how easily a software application can be used. On the other hand, accessibility testing services ensure that a software application is accessible to all, irrespective of technological or physical means. It includes people having screen readers to those having mobile phones, slow modems, or PDAs.
Accessibility testing is crucial because it focuses on verifying usability and ensures that every individual can use it efficiently, including people with disabilities, consisting of physical, speech, cognitive, visual, auditory, language, learning, and neurological disabilities. Thus, it’s crucial as it ensures an application to be available to all, which increases the usage of that software application.