What is the differnce between IP printer and network printer?

I doubt if there is one. A network printer is one that is available to any device on the network, An IP printer would indicate the same.

What is the difference? IP stands for Internet Protocol. The IP address is the address of the device. What the device is does not matter.

IP address can be used for an Intranet (Internal Network) or the WWW.

When the device is installed, it is configured for use on the network and then the address is assigned to it via software, unless of course you want to figure out the sub-net and network addresses already in use (nightmare).

All the network knows is that this device is a printer. The device drivers on your computer take care of formatting the data to be usable by the printer.

Now, "How is the device shared and connect are different questions." For example, you could have a network connection port on a Network Adapter inside of your printer to handle traffic right off the network connection port. You can share the device off your PC (which means that both the PC and the printer have to be on in order for anyone to have access to the device) via the parallel, serial or USB shared ports.