Currently, there is quite a large number of services on the Internet that provide workers with an entire range of resources. Among them are e-mail, a file archive system that provides storage and forwarding of files of various types, a service designed to manage remote computers in terminal mode, and many others. The listed services are standard: the principles of building client and server software, as well as interaction protocols, are formulated in the form of international standards. Consequently, software developers are obliged to meet general technical requirements in practical implementation.
However, along with standard services, there are also non-standard ones that represent the original development of a particular company; they may not be web-based. As an example, various systems, such as Instant Messenger, radio and video broadcasts, etc., can be used. In my opinion, although these servers are not web-based, they can still be considered services.