# API basics

Understand authentication, requests and API behavior.

Understand authentication, requests and API behavior.

- [Getting started with the Payroc API](/knowledge/api-basics/getting-started)
- [API keys](/knowledge/api-basics/api-keys)
- [Hypermedia as the engine of application state (HATEOAS)](/knowledge/api-basics/hateoas)
- [Glossary](/knowledge/api-basics/glossary)
- [Units of measurement](/knowledge/api-basics/unit-of-measure)