NOD is an organization that believes in Kane as the prophet that prophesized the alien tiberium crystal that is destroying the earth as a catalyst for the next stage of human evolution and discovery. They are at war with the Global Defense Initiative (GDI) which is trying to rid the world of tiberium. GDI considers NOD a terrorist organization.
The core of NOD is very well trained and using the latest technology that they develop on their own with flavors of exoticism attached to most of their high tech equipment. They use Cyborgs, Walkers, laser based hover crafts, etc.
The brunt of NOD infantry and terrorists come in numbers from the war ravaged yellow zones that have joined NOD to fight the people they feel are oppressing them....GDI.
Kane is obsessed with ascension....to the point that he provoked an ion cannon blast on liquid tiberium to attract attention of alien visitors who have come to harvest tiberium and build portals to galaxies away. Kane wants to use the portals to escape Earth.