ISO 9001 is a quality management system standard that can be applied to any type of organization. It is not specific to laboratories.
ISO 15189 is a quality management system standard specific to laboratories. It includes all of the requirements of ISO 9001 but also has additional requirements related to the specific nature of laboratory work.
ISO 17025 is a laboratory accreditation standard. It includes all of the requirements of ISO 9001 and ISO 15189 but also has additional requirements related to the specific process of accreditation.