Change management vs. Release and Deployment management

Change Management process manages changes. It does not implement them. That's done by Release and Deployment Management process. Change Management is authorizing changes i.e. different stages during change implementation (by Release and Deployment Management).
Process flow charts are different for those processes. Read the following articles to learn more:
ITIL V3 Change Management – at the heart of Service Management https://advisera.com/20000academy/knowledgebase/itil-v3-change-management-at-the-heart-of-service-management/
Elements of Change Management in ITIL https://advisera.com/20000academy/blog/2013/04/23/elements-change-management-itil/
ITIL Release and Deployment Management Part I – General principles and service testing https://advisera.com/20000academy/blog/2014/01/15/itil-release-deployment-management-part-general-principles-service-testing/
ITIL Release and De ployment Management Part 2 – deployment methods and early life support https://advisera.com/20000academy/blog/2014/01/28/itil-release-deployment-management-part-2-deployment-methods-early-life-support/

Authorized change is interface/connection between Change Management and Release and Deployment Management.