Final answer:
The prefix 'milli' in the metric system represents a factor of 1/1000 or 0.001. It is commonly used in measurements such as millimeters, where 1000 mm equals 1 meter.
Step-by-step explanation:
The metric system uses a variety of prefixes to denote different units of measure that are factors of ten. The prefix milli indicates a factor of 1/1000 or 0.001. Therefore, when applied to a meter, a millimeter (mm) represents 1/1000 of a meter. This is also written as 1000 mm = 1m. Metric prefixes are derived from Latin or Greek terms, and make conversions between units simple because they are all based on powers of ten.
For example, while the prefix kilo- represents a factor of 1,000 (a kilometer is 1,000 meters), the prefix centi- means 1/100 (a centimeter is 1/100 of a meter). It's essential to become adept at relating these prefixes to the corresponding factors of ten, especially in fields like chemistry where they are widely used.