Refers to the concept that people with disabilities are able to access and use a product or system, including with the help of assistive technologies. For example, an “accessible” web site may be designed so that the text can be enlarged by the user, rather than having a fixed font size, or may be designed so that it can be interpreted and “read out loud” by screen reader software used by people who are blind or have low-vision.
Assistive technologies:
Adaptive, rehabilitative devices that promote greater independence for individuals with disabilities by changing how these individuals interact with technology. Examples include alternative input devices (e.g., head or foot mouse, puff- and-sip switches, speech recognition), screen magnifiers, screen-reading software and speech recognition software.
Definitions for the term disability vary widely, arising from medical or social perspectives. Commonly accepted disabilities include (but are not limited to) impairment of one or more senses, cognitive disabilities, and mobility limitations.
Examples of common disabilities:
  • Auditory impairments — such as deafness
  • Cognitive disabilities — a very wide range of impairments that affect the ability to process, understand and remember on-screen content, but which are not intellectual impairments. Examples include dyslexia, autism and attention deficit disorder. 
  • Physical impairments that affect manual dexterity— such as Repetitive Stress Injury, Carpal Tunnel Syndrome, arthritis, conditions that cause tremors
  • Physical impairments that severely limit or prevent the use of the hands, that may result from conditions such as cerebral palsy, paralysis, or congenital limb abnormalities. 
  • Visual impairments — such as blindness, color blindness, low vision, and impaired field of vision
Screen reader:
A software application that attempts to identify and interpret what is displayed on the screen, translating the information usually to speech. Screen readers are relied on by people with no functional vision, but software that reads out on-screen content may also be used by people who have difficulty reading, because of a visual or cognitive impairment.
A standard is a set of requirements, specifications, characteristics, or guidelines that can be used to measure products, processes, and services. A standard can provide an incentive for compliance, and may be required by a customer, even though there is no legal requirement for adhering to them.
Examples of standards for accessibility:
Refers to how easily, effectively, and efficiently people, including people with disabilities, can use a product or system to achieve their goals, and how satisfied they are with the experience. The definition can be extended to user experience, covering a more subjective quality of enjoyment.
Voice recognition (or speech recognition):
A software application that enables a computer to accept voice commands. This allows for little or no use of the keyboard and mouse.