In the US, Disability is defined roughly in two ways. The Americans with Disabilities Act 1990 defines disability as "a physical or mental impairment that substantially limits one or more major life activity. This includes people who have a record of such an impairment, even if they do not currently have a disability. It also includes individuals who do not have a disability but are regarded as having a disability." - ADA National Network
In contrast, the U.S. Social Security Administration uses a legal definition of disability that relates specifically to the inability to do "gainful employment" due to a "medically determinable mental or physical impairment". - Social Security Administration
Today, most people with disabilities and disability researchers advocate for the social model of disability. This conceptual view of disability links dis-ability to various social factors that inhibit people's ability to do things. This model is directly opposed to the medical model of disability which asserts that having specific medical conditions means you are disabled. Most importantly, the social model highlights the connections between physical and digital environments, their design, and the consequent ability to maneuver within those spaces. The influence of the design of an environment and its resulting accessibility cannot be overstated. For example, if a wheelchair user's home is accessible and the paths and spaces to work, worship, shop, and have fun are accessible, then they are able to do everything in their life and thus wouldn't have a disability.
The Americans with Disabilities Act is a landmark human and civil rights bill that has articulated the need for renovation and changes in service policies. There is much work to be done to make our policies, services, and physical and digital environments accessible. You can make a difference by advocating for more accessible policies and spaces at work, at home, and in the city, state, and country where you live.
Libraries provide services to specific communities and society at large. This means that we provide services to people with disabilities.
Recent statistics on Library Professionals by the Department of Professional Employees show that the library workforce tends to be older than the average worker (31.5% over 55 in 2018). Stemming from broader attitudes towards aging, Ageism is a common issue in library workplaces, especially related to the adoption and use of technology. Ageism is rooted in perceptions about person's ability or in-ability to perform or understand their duties and thus, also affects younger workers in library workplaces.