Apps inside ChatGPT can call outside services during a chat.
Your chat box gets a tiny service counter. Ask for help, and ChatGPT can call in the right helper.
These apps bring outside tools into your chat. They may need your OK before doing sensitive jobs.
ChatGPT
ChatGPT Apps add outside services and screens to a chat.
API
ChatGPT Apps use APIs to connect to outside data and services.
AI App Store
Developers can submit ChatGPT Apps there for people to find.