The spot motion that leads to magnetic shear and flares is almost always in an Emerging Flux Region. However, flux is somewhat more likely to emerge near where it has previously emerged, so even mature spots bear a little watching. Normal EFR development results in a fairly peaceful group which may have produced a few minor flares. In declining groups, the smaller f polarity spots usually vanish before the dominant spots begin to decay. Most groups finally decay into a single p spot with no plage, which then slowly shrinks and dies out.
Deltas are some of the largest and most active areas on the sun.
The opposite polarities are generally within two degrees of each other. Deltas usually form in one of three ways. Large satellite polarity areas emerge close to existing spots so that the expansion of the emerging flux region pushes a p spot into an f spot or vice versa. It only forms from emerging umbrae, not plage. If the new dipole emerges into plage only, modest flares may occur without delta spot group formation.