ISO 9001 is the international standard which specifies requirements for quality management systems (QMS). Organisations implement requirements of the standard to demonstrate the ability to consistently provide products and services that meet customer and regulatory requirements. It is the most popular standard of the ISO 9000 series and the only standard in the series to which organisations can certify. The new version of ISO 9001 was released in September 2015 and changes made in ISO 9001:2015 are more significant than those produced during the 2008 revision. On first view are clearly seen changes in structure of ISO 9001:2015, where the number of sections expanded from 8 to 10 but this paper explain the main changes in understanding quality which include context of organisation, risk based thinking, knowledge as resource and leadership.