In general, the word 'client’ is used in IT to refer to hardware or software that accesses server services. The server coordinates these services and the external systems are their clients.

One aspect of this involves detailing the rise of the Internet and the use of browsers to offer client services directly through websites.

However, smart client applications evolved beyond this in order to provide security for these services, and to streamline the offering of services to individual users or clients. In addition, the types of client devices used also proliferated.

Where most clients of the 1990s were desktop or laptop computers, new client devices include different kinds of mobile devices or smartphones. In addition, smart client services share various characteristics, including the use of local resources, a more always-on connection model and better features for updates or upgrades.