Dish being part of a paraboloid has a curved shape.
A typical dish antenna is shown in the figure above.
Function of a dish antenna is to receive electromagnetic signals in a designated band of frequencies from satellite.
The parabolic reflector of the dish reflects and focuses the received signal at its focal point. The feedhorn is front-end of a wave-guide, which collects the signals near the focal point and passes them to a low-noise block downconverter (LNB) for further processing.
Direct broadcast satellite dishes use an LNBF, which is integrated LNB and feedhorn.