The server processes each user request and gives a specific answer to it. This response goes to the browser that is installed on the user's computer, and the browser shows exactly what the server is giving it, different types of errors, redirects, or a website page. All errors have their own coding, and the machine understands them "in its own way". It contains a certain algorithm of how to act at certain points. Let's consider the most common errors during server operation (5xx): - 500- It means an error when performing any operation on the server that failed. It is easily eliminated by competent specialists. - 501 - Appears when we perform a prohibited action. - 502 BadGateway. We receive this code when we cannot receive a response from a third-party resource. - 503 - This error appears when the required service is temporarily unavailable. Retry-After is added if you specify the time to restore the work. This error very often appears on weak hosting as a result of multiple overloads. - 504 - Encoding appears when the timeout of another resource is exceeded. - 505 -. If you receive such a message, then the server does not support the version of the HTTP protocol. What should be done when such errors appear? Some of the errors are temporary, so they are practically harmless, since your website will quickly restore its performance and will work in the same mode. And some of the errors can lead to a stop of your website, and then you will need to solve this problem in order to improve the website's performance. Therefore, if an error occurs, you need to view the records that are stored in the server logs. You will find useful information there. And finding any kind of errors on the website is easy with Sonar.Network. Add your website to monitoring and in two clicks you can see all the errors of your website or unavailable pages.