model API
A way for your software to send text to an AI model hosted by someone else and get an answer back.
Many companies do not run AI models themselves. They send each request over the internet to a provider's model through an API. An API is a standard doorway for one piece of software to talk to another. The provider runs the model and returns the answer. You usually pay per use, often per token.
Think of it as
Like ordering from a restaurant's delivery service instead of building your own kitchen. You send the order, the food arrives, and you pay per order.
Example
A small online shop adds a button that writes product descriptions. Each click sends the product details to a model API and gets a description back, billed per use, with no AI servers for the shop to manage.