Accessibility is the degree to which a product, device, service, or environment is available to people. In other words, accessibility is the "ability to access" and use a service or a product by all members of the society, regardless of their physical abilities.
The physical environment can either facilitate or limit the independence for persons with disabilities. Accessibility should be considered in both public and residential buildings. A barrier free environment will allow a person with a disability to live more independently within their own home as well as access public buildings and participate in community activities. Barrier free design assists not only those with disabilities (including wheelchair users), but also pregnant women, the elderly and even parents with children in strollers.
By exploring the corresponding sections of this website (Buildings, Streets and Transport) you will find some tips on providing accessible environment for people with different kinds of disability.
The complete accessibility of the environment, products and services for usage by the widest range of people possible is called "Universal Design" and includes products, services and spaces that are completely accessible and usable by the elderly, persons with various types and severities of disabilities, pregnant women, obese persons and members of all social groups despite their physical or cognitive abilities, age and other factors. Universal Design promotes diversity through creation of places, things, information, services and policies which can easily be used by all members of the society.

The Seven Principles of Universal Design

Equitable Use: The design provides the same means of use for all users - identical whenever possible, equivalent when not, avoids segregating or stigmatizing users.

Flexibility in Use: The design accommodates a wide range of preferences and abilities. It provides choice in methods of use, accommodates right or left handed access.

Simple and Intuitive Use: Use of the design is easy to understand, regardless of the userís experience, knowledge, language skills, or current concentration level.

Perceptible Information: The design effectively communicates necessary information to users, regardless of ambient conditions or users' sensory abilities.

Tolerance for Error: The design minimizes adverse consequences of accidental or unintended actions by providing fail safe features and warnings of hazards.

Low Physical Effort: The design can be used comfortably with minimum fatigue by allowing users to maintain a neutral body position and minimizing repetitive actions.

Size and Space for Approach and Use: Appropriate size and space is provided for approach, reach, manipulation, and use, regardless of userís body size or mobility.