A proton spectrum of a simple molecule
SOURCES OF INFORMATION
Chemical shift (frequency). The precession frequency of the nucleus depends on the magnetic field and is sensitive to local environment. Proton chemical shift varies by ~ +/- 8 ppm relative to the frequency of water.
'Coupling': Interactions between nuclei. Depends on geometry, distance and chemical bonding.
Return to equilibrium magnetization depends on molecular motions, interactions between nuclei, and many other things.