Essentials 4 Data Support is an introductory course for those people who (want to) support researchers in storing, managing, archiving and sharing their research data. Essentials 4 Data Support is a product of Research Data Netherlands. The course takes a look at the different aspects involved in supporting researchers with their data along the research cycle. It starts with defining the basic concepts and terms involved in RDM support. It moves into the planning phase, where data management plans and preregistrations. During the research phase, topics such as data collection, data formats, storage, organization, documentation and virtual research environments are covered. The harvest phase covers data publication, archives and repositories, as well as a chapter about EOSC and finding data. An additional module is dedicated to legislation and policy and a final section about data support and data stewardship is provided. The online version of the course is free.