When can a printer be called a Jini-enabled printer? How is it different from other printers?
When a printer has a Jini-based Service embedded in it, it can be called a Jini-enabled printer. By embedded, I mean that the Jini service is already installed in the printer's ROM along with other printer software. So when such a printer comes up on the network then it can publish its services in the appropriate Jini Lookup. Any Jini-based client can use the Jini Lookup to find if there are any Jini-based printer services registered, then the client can use the published interfaces of these Jini-based service to access the printer.
It is different from a normal printer in that a client doesn't need to bother about printer drivers, configurations, etc. on the client machine. A simple Jini-based client could be used at the client side to access the services offered by the Jini-enabled printer. Secondly, normal printers have to be installed before being used - this might require special hardware and software installation - while Jini-based printers register themselves in the Jini Lookup when they boot up, so installation is not actually required.