HTTP Status Codes
also response codes
Three-digit numbers a server returns to indicate a request's outcome, grouped as 2xx success, 3xx redirect, 4xx client error, and 5xx server error.
Analogy
Like a delivery receipt stamp telling you whether your package arrived, was refused, or got lost.
Why it matters
Reading status codes is how you debug failing webhook and API calls in your automations.
In practice
A 401 from an API call tells you the api key is missing or invalid, while 200 means success.