A Postman Collections is a machine-readable, exportable, and forkable collection of API requests. Postman Collections can be generated from an OpenAPI, running a web application in Chrome using the Postman Interceptor, or hand-crafted to call specific APIs. A collection comes with documentation built in and runs via the Postman application on the desktop, in the cloud, and via CI/CD pipelines.
Postman Collections are a great way to define API testing and automation, making for a more executable representation of what an API does than OpenAPI which acts a source of truth for publishing documentation and mock servers, generating SDKs, and generating even Postman Collections for different purposes. Postman Collections should be part of any API contract, accompanying OpenAPI and other artifacts, making it easy for anyone to put an API to work without writing any code.