What is the meaning of metrics?

noun

• A function of a topological space that gives, for any two points in the space, a value equal to the distance between them.
  • synonyms: metric function, metric
• A decimal unit of measurement of the metric system (based on meters and kilograms and seconds. )
  • usage: "convert all the measurements to metric units"; "it is easier to work in metric"
  • synonyms: metric unit, metric
• A system of related measures that facilitates the quantification of some particular characteristic.
  • synonyms: system of measurement, metric
• The study of poetic meter and the art of versification.
  • synonyms: prosody