Definition:
An add-in (or add in) is a small program that works from within a larger application program. An add-in has limited features but only requires limited memory resources.
Add-ins are created individually for specific programs and are installed separately. They then become part of the parent program. An add-in cannot run on its own.
Also Known As: plug-in, add-on
Alternate Spellings: add in
Common Misspellings: addin
Examples:
The PowerPoint add-in called Opazity, created transparencies and out of focus areas on several of the slides.