Each category is divided into sub-categories that allows you to select the source and target units:
Currencies: By abbreviation (USD - US Dollar), By Country name (United States - Dollar, and by currency name (Dollar, Us).
Measurements: Angles, Area, Density, Energy, Force, Kitchen measurements, Length, Power, Pressure, Temperature, Time, Torque, Velocity, Volume, Weight.
Time: Time Zones (GMT, PST, etc.), Local Times (United Kingdom, Los Angeles, etc.)