In common usage, a scoop is any specialized spoon

Spoon

A spoon is a utensil consisting of a small shallow bowl, oval or round, at the end of a handle. A type of cutlery , especially as part of a place setting, it is used primarily for serving. Spoons are also used in food preparation to measure, mix, stir and toss ingredients...

 used to serve food.
In the technical terms used by the food service industry and in the retail and wholsale food utensil industries, there is a clear distinction between two types of scoop: the disher, which is used to serve ice cream

Ice cream

Ice cream is a frozen dessert usually made from dairy products, such as milk and cream, and often combined with fruits or other ingredients and flavours. Most varieties contain sugar, although some are made with other sweeteners...

, measure a portion e.g. cookie dough

Cookie dough

Cookie dough refers to a blend of cookie ingredients which has been mixed into a malleable form which has not yet been hardened by heat. The dough is often then separated and the portions baked to individual cookies, or eaten as is....

, or to make melon ball

Melon ball

Melon balls are balls of melon made using a melon baller that varies from around 1 centimetre to 3 centimetres . They are generally used in fruit salad.-Melon ballers:...

s; and the scoop which is used to measure or to transfer an unspecified amount of a bulk dry foodstuff such as rice, flour, or sugar.

Dishers are usually hemispherical like an ice cream scoop, while measuring scoops are usually cylindrical, and transfer scoops are usually shovel

Shovel

A shovel is a tool for digging, lifting, and moving bulk materials, such as soil, coal, gravel, snow, sand, or ore. Shovels are extremely common tools that are used extensively in agriculture, construction, and gardening....

-shaped.

Some dishers have mechanical devices which help get the contents out of the scoop. Some ice cream scoops are liquid-filled to keep the ice cream from freezing to the scoop's metal. Traditionally dishers are sized by the number of scoops per quart

Quart

The quart is a unit of volume equal to a quarter of a gallon, two pints, or four cups. Since gallons of various sizes have historically been in use, quarts of various sizes have also existed; see gallon for further discussion. Three of these kinds of quarts remain in current use, all approximately...

 but may also be sized by ounces, the diameter

Diameter

In geometry, a diameter of a circle is any straight line segment that passes through the center of the circle and whose endpoints are on the circle. The diameters are the longest chords of the circle...

 of the bowl, or the number of tablespoon

Tablespoon

A tablespoon is a type of large spoon usually used for serving. A tablespoonful, the capacity of one tablespoon, is commonly used as a measure of volume in cooking...

s they hold.

Disher Scoop Sizes

Scoop Number (Scoops per Quart)	Fluid Ounces (fl. oz.)	Spoon Equivalent (Tea=tsp. Table=TBS.)	Metric (millilitres)	Diameter (inches)
6	5.3		158
8	4.0		118
10	3.2		95
12	2.7		80	2 3/8
16	2.0		59
20	1.6		47
24	1.3		38
30	1.1		33
40	0.8		24	1 5/8
60	0.53		16
70	0.46		14	1 1/4
100	0.32		9