Pint is an imperial and U.S. customary volume unit. There is one type of pint in imperial system and 2 types (liquid and dry) in united states customary system. It is widely used in daily life, such as measuring beer, milk. The abbreviation is "pt".
Fluid ounce is an imperial and U.S. customary volume unit. Fluid ounces are volume units and should not be mistaken with ounces which is mass (weight) unit. The abbreviation is "fl oz".