The terms "legal cup," "imperial cup," and "one cup" refer to different measurement systems used to define the volume of a cup. The main differences lie in the specific values and standardization of these measurements. Legal Cup: is a unit of measurement used in the United States for volume. It is defined as exactly 240 millilitres (ml) or approximately 8.12 fluid ounces (fl oz). This value is standardized by the United States Department of Agriculture (USDA) and the Food and Drug Administration (FDA) for nutritional labelling purposes. The legal cup is used in official nutrition guidelines and labels in the United States. Imperial Cup: is a unit of measurement used in the United Kingdom British Imperial System and some other Commonwealth countries for volume. It is defined as 10 imperial fluid ounces, which is equivalent to approximately 284 milliliters (ml). The imperial system is used in these countries for most everyday measurements, including cooking and baking. One Cup: The term "one cup" is not a standardized measurement unit but is often used colloquially to refer to a standard measuring cup used in cooking and baking. In the United States, the standard measuring cup typically holds 8 fluid ounces, which is equivalent to the legal cup measurement. It is important to note that the size of a measuring cup can vary by region, and other countries might have different standard sizes for their measuring cups.