What do you mean by “Reference standard” and “Working standard

Reference Standard: 

A substance that has been shown by an extensive set of analytical tests to be authentic material that should be of high purity. This standard may be obtained from an officially recognized source or may be prepared by independent synthesis or by further purification of existing production material. 

Working Standard: 

A substance of established quality and purity, as shown by comparison to a primary reference standard, used as a reference standard for routine laboratory analysis.