Tactics: The NWP was more extreme taking political action in the form of protest whereas the NAWSA used the help of men to access the political system.
The two groups essentially wanted the right to suffrage but the NWP had a larger political agenda. They wanted to also get an Equal Rights Amendment passed in addition to the right to vote. Their leadership often used public protest, picketing, and hunger strikes to get action. The NAWSA worked with men and politicians through non-violent and more "feminine" means of getting attention.