ISO 9001:2015 is the latest revision of the ISO 9001 international standard that specifics requirements for a quality management system (QMS). The requirements are contained within seven clauses:
Organizations will get certified to this standard in order to demonstrate their ability to consistently provide products and services that meet customer, statutory and regulatory requirements. Certification is granted by accredited certification bodies (registrars) that will audit an organization at planned intervals to confirm conformance to the ISO 9001:2015 standard.
The standard can be applied to any organization. Its benefits include enhanced customer satisfaction, standardized processes, improved quality of products and services, and a culture of continuous improvement.
The 2015 revision has replaced ISO 9001:2008. Organizations needed to be transitioned over by September 2018, if you did not meet this deadline your ISO 9001 certificaiton is now void.