The image below shows the Rohloff hub gearing system. The design and features are similar to the classic 3 speed Sturmey Archer hubs of the 60's & 70's. The derailleur systems are susceptible to damage from bumps and weather. The internal hub systems require much less maintenance. Another advantage is 14 speed system does not have any duplicate gears. Gear ratios are measured in gear inches. With typical 3 front sprocets/8 rear you have 24 available gears but there may be 3 or 4 duplicates because the gear inches are the same. Another difference is the ease of use of the internal gear hub. You click one way to get a higher gear and the reverse gives you a lower gear. With derailleur systems you have two derailleurs to keep track of. The final cool ability of the Rohloff is that you can switch gears while standing still. No other system offers this. If you're at a stop light and haven't changed to a starting gear it's not too late. With derailleur or other gear systems you must be moving to switch.

It was a bit of a challenge to understand and install the cable system which actuates the shifting process. It's very different from derailleur systems.