Because of the terminological overlaps, the interdisciplinary nature of the European Open Science Cloud (EOSC) initiative creates the need for a glossary that facilitates and improves the communication between the different communities involved. Resulting from a continuous collective effort, the EOSC Glossary proposes a terminology that is based on the analysis of the EOSC related documents and the review of the terminological collections, the standards and the specific literature connected to the concepts that characterise the EOSC domain, providing a starting point for the standardisation process. The methodology followed for the realisation of the EOSC Glossary is in line with the standards ISO 704:2009 Terminology work — Principles and methods, ISO 860:2007 Terminology work — Harmonization of concepts and terms, ISO 1087:2019 Terminology work and terminology science — Vocabulary and ISO 10241-1:2011 Terminological entries in standards — Part 1: General requirements and examples of presentation.