1) In general:
Standards are something established for use as a rule or basis of comparison in measuring or judging properties or activities.
2) In technology:
Technical standards are universally accepted agreements on the nomenclature, form, units of measurement etc., applied to facilitate common ground fore evaluation and interchangeability of products.
3) In law:
Legal standards are binding prescriptions (laws, ordinances, rules, and regulations).
Industrial Standards are normally a collection of technical specifications for designated products or product groups.