Accessibility! My favorite subject- wish I had began learning in grade school, because now I feel that I'll be spending the entirety of my adulthood learning. However, it's never too late to contribute to making the world a better place, and practice more equitable design but I digress. Now to actually answer the question.
Accessibility, in the TL;DR version, is making products, services, and environments easy to use for people with disabilities. There are hundreds of disabilities- and all can be categorized as either visual, auditory or hearing, speech (sometimes motor), cognitive (including reading, intellectual, and learning), mobility, flexibility, and body structure disabilities. It should been known that types of disabilities vary by culture and region. For example, in UK, chronic pain is considered a disability. You know what- I believe that the U.S. could take notes. But no place is perfect- unless you're in Sweden or Barbie World, both of those places seem pretty perfect by many people's standards.
It is my adamant belief that Accessibility is the next wave of innovation, and the people who benefit from accessibility will be the next generation of innovators. They simply need access to the knowledge - because knowledge is powerful. Most websites have insurmountable barriers that prevent users from accessing valuable information. What most organizations don't know, is that inaccessible websites often cause problems for the typical user as well.
Use this website as a resource to enlighten yourself and others to the benefits of accessibility, deepen your understanding of marginalized communities, and increase your impact in nearly any role.