This document discusses disability, definitions of disability, conceptual models of disability, and inclusion of people with disabilities. It defines disability according to the World Health Organization as an interaction between a person's impairments and their environment. Approximately 650 million people, or 10% of the world's population, live with a disability. Most live in developing countries where they face higher risks of poverty. The document advocates for inclusive development and universal design to ensure full participation of people with disabilities in society. It also compares the medical and social models of conceptualizing disability.