Disablism - A set of assumptions (conscious or unconscious) and practices that promote the differential or unequal treatment of people because of actual or presumed disabilities.
People who do not have a disability or who are not close to someone who does, might not understand how the world is wired for non-disabled people. It may be invisible to those who do not have disabilities. It is sometimes not intentional, but in certain circumstances, it is very intentional.
An ableist society is said to be one that treats non-disabled individuals as the standard of ‘normal living’, which results in public and private places and services, education, and social work that are built to serve 'standard' people, thereby inherently excluding those with various disabilities.
Persons with disabilities face many kinds of barriers on a daily basis. These can be physical, attitudinal or systemic.