Metric
From Wikinfo
The Metric System is a common term for the International System of Units.
In mathematics, a metric (also called distance metric) is an abstraction of the notion of distance; it is used to define metric spaces. The article on metric spaces contains a detailed discussion of the topic.
An important special case is the metric that turns a manifold into a Riemannian manifold. Such a metric allows to introduce geodesics and to measure distances and angles on the manifold.
References
- Adapted from the Wikipedia article, "Metric" http://en.wikipedia.org/wiki/Metric, used under the GNU Free Documentation License
