Photospheric layers of sunspots and pores

Sunspots and pores appear as a consequence of interactions between strong magnetic fields and moving plasma. A wide variety of small-scale features, presumably of convective origin, are observed in photospheric layers of sunspots and pores: Umbral dots, light bridges, penumbral filaments, and penumbral grains. Each type of features has specific morphological, photometric, spectral, and kinematic characteristics due to a broad range of magnetic field strengths and inclinations in umbrae and penumbrae. Spots and pores modify velocity fields in adjacent photosphere and subphotospheric layers. Recent high-resolution spectral, broad-band, and helioseismic observations of the structure, dynamics, and magnetic fields of sunspots and pores, together with theoretical interpretations, are discussed in this review.