NMEA 0183 and 2000 are completely different. They are not 'languages' but really specify the electrical connection between two (or more) devices. NMEA 0183 is like serial communications that old computers used. NMEA 2000 is more like Ethernet networking.
The two are not interoperable at all.
Most DEVICES (plotters, radios, etc.) that can accept NMEA 2000 INPUT will also accept NMEA 0183, but this is because the device will have two or more communication powers.
NMEA 0183 is an old standard that has been around for a long time and will continue to be around for a long time. It is simple and cheap. It is designed so ONE piece of equipment (TALKER) to communicate to another piece of equipment (LISTENER). For example, a DSC VHF radio can obtain GPS location position from a GPS, or a wind speed and direction instrument can send information to a chart plotter with GPS speed so the plotter can calculate TRUE wind information. The information can only flow from one device to another device. You can't connect multiple devices NMEA 0183 device together unless you add additional gear (multiplexor). NMEA is SLOW (2400 baud typically) and requires you to connect little tiny wires.
NMEA 2000 is a newer standard that supports true networking. Think of computer networking where there can be multiple devices all communicating at the same time and to each other. With a NMEA 2000 network there is a network backbone (wire) that ALL devices connect too. You can have a GPS sending location information, water speed transducer sending speed through water information, wind instruments, AIS, Autopilot, etc. It is simple to add displays that allow you see whatever information you want. To add another NMEA device all you need to do is plug it in to the network and it starts working immediately.
Some additional tidbits:
Raymarine used to have a non-standard interface called SeaTalk. This is now obsolete as Raymarine has gone to SeaTalkNG (Next Generation) which is really just NMEA2000.
A good place to learn more about boat electronics is the Panbo Blog run by Ben Ellison. Visit it here:
Panbo: The Marine Electronics Weblog
My own opinion is that if you just want a simple system, say chart plotter with GPS connected to DSC VHF radio, then NMEA 0183 is fine. If you want something more involved, say you want an autopilot that can get information from the plotter, and you want to add wind and boat speed through water as well, you are better off with NMEA 2000.