Accessibility - having a place, environment, or event that is set up to be barrier free for all individuals to access (https://youth.gov/youth-topics/inclusion-and-accessibility)
Accessible - easily used or accessed by people with or without disabilities (https://www.merriam-webster.com/dictionary/accessibility)
Accessible Design - a design process in which the needs of people with disabilities are specifically considered (https://www.washington.edu/accesscomputing/what-difference-between-accessible-usable-and-universal-design)
Universal Design - the design of products and environments to be usable by all people, to the greatest extent possible, without the need for adaptation or specialized design (https://www.washington.edu/accesscomputing/what-difference-between-accessible-usable-and-universal-design)
Usable Design - a design process in which products that are created are easy and efficient to use (https://www.washington.edu/accesscomputing/what-difference-between-accessible-usable-and-universal-design)