In human-computer interaction, computer accessibility (also known as Accessible computing) refers to the accessibility of a computer system to all people, regardless of disability or severity of impairment. It is largely a software concern; when software, hardware, or a combination of hardware and software, is used to enable use of a computer by a person with a disability or impairment, this is known as Assistive Technology.

There are numerous types of impairment that impact computer use. These include:

• Cognitive impairments and learning disabilities, such as dyslexia, ADHD or autism.
• Visual impairment such as low-vision, complete or partial blindness, and color blindness.
• Hearing impairment including deafness or hard of hearing.
• Motor or dexterity impairment such as paralysis, cerebral palsy, or carpal tunnel syndrome and repetitive strain injury.

These impairments can present themselves with variable severity; they may be acquired from disease, trauma or may be congenital or degenerative in nature.

Accessibility is often abbreviated to the numeronym a11y, where the number 11 refers to the number of letters omitted. This parallels the abbreviations of internationalization and localization as i18n and l10nrespectively.