  Photospheric magnetic fields are studied using synoptic maps from 1976 to
2003 produced at the National Solar Observatory, Kitt Peak (NSO/KP). Synoptic
maps were averaged over the time interval of nearly three solar cycles (Solar
Cycles 21-23). The change in the latitudinal distribution was considered for
the following groups of magnetic field values: B = 0-5 G, B = 5-15 G, B = 15-50
G, and B>50 G. Magnetic fields in each of the above groups have common
latitudinal distribution features, while for different field groups these
features are significantly different. Each of the groups is closely related to
a certain manifestation of solar activity. Strong magnetic fields are connected
with two types of solar activity: active regions (magnetic fields B>15 G)that
are related to sunspot zones, and polar faculae (magnetic fields 50 G > B > 15
G) that occupy latitudes around 65$^\circ$-75$^\circ$. Fields from 5 to 15 G
occupy the polar regions and are connected with polar coronal holes (the global
solar dipole). Fields of B<5 G occupy a) the equatorial region and b) latitudes
40$^{\circ}$-60$^\circ$.
