Definition: Each (ea) is a unit of quantity that signifies a single item or unit. It denotes one individual object or element within a group or set.

History/origin: The term "each" is a basic English word with origins in Old English. It has been used for centuries as a fundamental way to refer to individual items within a group.

Current use: The unit "each" is universally used in a wide range of contexts, including retail, inventory management, manufacturing, and everyday conversations. It provides a straightforward way to specify the number of individual items being referred to.