p700 is photosystem I. It includes chlorophyll a 670, 680, 695, 700, Chlorophyll b, carotenoids. The active reaction center of photosystem is p700, as it absorbs light of a wavelength longer than 680nm.
P680 or the photosystem II has the following pigments: chlorophyll b, 660, 670, 680, 695, 700, phycobilins, and xanthophylls. The active reaction center, in this case, is p680 of chlorophyll a, as it absorbs the light having a wavelength shorter than 680nm.
