Definition:Distance


 * Metric spaces:
 * A distance function in a measure defining a metric space.
 * The distance between sets is the minimum distance between elements in two subsets of a metric space.


 * Geometry:
 * The distance between two points $A$ and $B$ is the length of a line segment joining $A$ and $B$.


 * Information theory:
 * The distance between two codewords of a given linear code is the number of corresponding terms which are different between those two codewords.