Four main aspects of umbral and penumbral fine structures are considered: brightness and morphology, magnetic field, velocity and oscillations. The author discusses a model in which penetrative convection produces peripheric umbral dots and upward flowing matter which is channeled outwards, pushing the magnetic field aside. The possibility of a non

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High resolution (better than 1arcsec) magnetograms obtained at the Sacramento Peak Vacuum Tower Telescope were used to study the decay of a small active region. The reduction process allows one to match intensity and magnetic pictures exactly.

The decay of a small solar active region is studied with high-resolution magnetograms. The reduction process made it possible to match intensity and magnetic pictures exactly. It is found that the granulation massages the magnetic concentrations and contributes to their fragmentation. Supergranules contribute to the decay of the pore by removing

Various possible decay laws (exponential, linear, parabolic) are tried to fit the observational material. The dependence of the decay rates on the spot's maximum area as well as their variation along the activity cycle are studied.