In plain language
It answers “who is calling?”, usually with a password, API key, or token.
Example
A workflow connects to a CRM using OAuth, proving it acts for a specific signed-in user.
Related terms
OAuth · API Key · Access Token · OAuth Scope
Common misconception
Authentication is not authorization; proving who you are does not decide what you are allowed to do.
Implementation guidance
Use the method each API recommends, prefer OAuth over shared passwords, store credentials in the platform’s connection manager, and connect with a dedicated service account.