There are two types of filters in general use in a power supply. They are called:

Power supply filter circuits are primarily classified by the very first component that the pulsating DC from the rectifier encounters. If the first component in the filter network is an inductor (choke) in series with the load, it is called a "choke-input" filter. If the first component is a capacitor in parallel with the load, it is called a "capacitor-input" filter. These two topologies have distinctly different characteristics. Capacitor-input filters yield a higher output voltage but poorer regulation, while choke-input filters offer a lower output voltage but excellent regulation. Terms like "choke output" or "capacitor output" are not standard classifications for basic power supply filter topologies.