Assistive technology (AT) refers to any item, piece of equipment, software program, or product system that is used to increase, maintain, or improve the functional capabilities of persons with disabilities. AT can be low-tech, such as communication boards made of cardboard or fuzzy felt, or high-tech, such as special-purpose computers. AT can also be hardware, such as prosthetics, mounting systems, and positioning devices, or computer hardware, such as special switches, keyboards, and pointing devices. AT can also be computer software, such as screen readers and communication programs, or inclusive or specialized learning materials and curriculum aids.

AT helps people with disabilities to perform functions that might otherwise be difficult or impossible, such as accessing computers or other information technologies. AT can also help people who have difficulty speaking, typing, writing, remembering, pointing, seeing, hearing, learning, walking, and many other things. Different disabilities require different assistive technologies.

AT promotes greater independence by enabling people to perform tasks they were formerly unable to accomplish, or had great difficulty accomplishing, by providing enhancements to, or changing methods of interacting with, the technology needed to accomplish such tasks. For example, wheelchairs provide independent mobility for those who cannot walk, while assistive eating devices can enable people who cannot feed themselves to do so.

AT services are any support that helps people with disabilities to choose, get, or use an AT device. Some examples of AT services include evaluation performed by a doctor or specialist, training to help a person learn what a tool can do and how to use it, and help with repairing a device. Without these services, assistive technology may not be effective.

Overall, assistive technology aims to allow people with disabilities to participate more fully in all aspects of life, including home, work, education, and recreation.