A server application can be defined as an application that accepts requests, processes them, and sends the corresponding responses to the client. Communication happens via some transport protocols, and usually, but not necessarily, the client and server applications are situated on different physical computers. The computer that runs the server application is usually referred to as the server.

There are many types of server applications. For example, a Remote Desktop Services software that allows us to open remote session to a Windows machine is a server application. Each user connection consumes a lot of server resources, but in this particular scenario, this is inevitable. This server application does not need to support hundreds or thousands of simultaneous users and is intended to be like this. However, if we imagine a website that allows only a few users to browse it simultaneously, it would be definitely a failure.

On the other hand, it is OK when a website user gets...