A unit of length used in marine navigation that is equal to a minute of arc of a great circle on a sphere. One international nautical mile is equivalent to 1,852 meters or 1.151 statue miles. Please not that this is different to a UK Nautical mile.
The metre is a unit of length in the metric system, and is the base unit of length in the International System of Units (SI).
As the base unit of length in the SI and other m.k.s. systems (based around metres, kilograms and seconds) the metre is used to help derive other units of measurement such as the newton, for force.