What is Jini?
Jini is an architecture for distributed computing. In particular, it addresses how to provide object services to clients, and how these clients find available services. Jini differs from other distributed object systems in that the services are assumed to be transient and the network unreliable. In other words, in a dynamic distributed environment clients and services come and go; the Jini architecture deals with this as a "normal" situation, instead of failing.
The Jini architecture is especially useful for mobile devices, since these can be expected to join and leave the network with regularity. However, Jini is just as useful in a more traditional client-server situation, where both the client and the server are software processes.