Liters (sometimes referred to as litre) are a special kind of unit for measuring capacity. One liter is equivalent to 1,000 milliliters (ml) and is mainly used to measure liquid capacity. They are used in both the metric and imperial systems of measurement. Liters have a long history, with the first use of the unit recorded in the early 18th century. The term was derived from the Greek word litron, which was used to describe a unit of volume. The original symbol for a liter was l, but it has since been replaced by the symbol L due to the development of capital letters in the alphabet. Due to the nature of how it is written, the liter has lent itself to a number of uses and applications. For example, most modern soda, beer and energy drinks come in cans or bottles that are clearly labeled with the volume in liters. It is also the standard unit of measure for fuel, with most gas pumps displaying the amount in liters per gallon. The liter is also used in pharmaceutical products and is the standard unit of measurement for most laboratory chemicals. Finally, it is used as a measurement of capacity in many industrial processes such as brewing and distilling. Overall, the liter is a versatile and important unit of measure that is used in a variety of industries and applications. Its long history and precise measurement makes it a reliable and trustworthy unit for measuring liquid capacity.