JMeter comes bundled with assertion components. Assertions are used to perform additional checks on samplers and are processed by default after every sampler in the same scope, except for in cases where they have been added as a direct child of a sampler. You can think of these as mini unit tests within your test plans that ensure the responses from the server actually work fine. For example, when you make HTTP requests in a web application, the server responses may respond with different HTTP header status codes, denoting the success or failure of your request. A status code of
200, for example, means the request succeeded,
401 means access was denied to the requested resource,
500 means an internal server error occurred ...