# Understanding HTTP Status Codes
HTTP status codes are essential indicators of the relationship between the client (browser) and the server. They are grouped into five classes, each representing a different category of response.
1xx InformationalRequest received, continuing process.
2xx SuccessThe action was successfully received, understood, and accepted.
3xx RedirectionFurther action must be taken in order to complete the request.
4xx Client ErrorThe request contains bad syntax or cannot be fulfilled.
5xx Server ErrorThe server failed to fulfill an apparently valid request.