This is an Electrolytic capacitor with 330µF of capacitance and 16V rating.
Electrolytic capacitors are used in huge quantities, They are able to provide a larger capacitance per volume than other types of capacitor. This gives them very many uses in circuits where high currents or low frequencies are involved. Electrolytic capacitors are typically used most in applications such as audio amplifiers of all types (hi-fi to mobile phones) and in power supply circuits.
Like any other capacitor, it is necessary to understand the advantages and limitations of these capacitors to enable them to be used most effectively.
330uF 16V DC Polymer Aluminum Through Hole Capacitor
An aluminum electrolytic capacitor, often only called an electrolytic capacitor, uses aluminum metal as one electrode, covered with a very thin layer of aluminum oxide as dielectric, and which has an the electrolyte as its second electrode.
Aluminum electrolytic capacitors are typically used in power supplies and DC-DC converters for smoothing and buffering rectified DC voltages in many electronic devices. They are also used in industrial power supplies. Aluminum electrolytic capacitors are polarized capacitors because of their anodization principle. They can only be operated with DC voltage applied with the correct polarity.