Plugin
Also called plugins
An add-on package for an AI app that bundles reusable instructions, reference files and connections to other services, installed from a directory.
A plugin is how an AI app gains a specialism without the app maker building it. Someone packages up what's needed for a job: instructions on how to do it (often as skills), reference material, and links to the services involved. You install it, and the assistant can now do that job properly.
The word has had 2 lives. ChatGPT first had plugins in 2023, then wound them down in early 2024 in favour of GPTs. In 2026 the name came back for something broader, and both ChatGPT and Claude now have plugin directories.
Treat a plugin like an app on your phone. It can read what you give it and act where you've connected it, so the same caution applies: trusted makers, the access it actually needs, and a clear-out now and then.
For example
A travel company's plugin lets ChatGPT search its real flight prices and follow its booking rules, instead of guessing from the web.
Put it to use
Where you'll meet plugin in ChatGPT, Gemini and Claude, how to use it there, and the mix-up most people make.
Daily Bytes Plus is in the Android app.