This is the fourth and last webinar of the “What is a Chemical webinar series” organized by the IUPAC WorldFAIR Chemistry project on Feb 17, 2023. In this webinar, 5 guest speakers (below) were hosted to deliver flash presentations. The talks covered various digital chemical descriptions. They were followed by a panel discussion. Moderator: Ian Bruno, IUPAC CPCDS and CCDC Speakers and Presentations: Henry Rzepa Imperial College London Media types: Interesting Enhancers of the F. A. I. and R. of FAIR Adnan Malik EMBL-EBI ChEBI: Chemical Entities of Biological Interest Oliver Koepler TIB - Leibniz Information Centre of Science and Technology Ontologies4Chem Alex Clark Collaborative Drug Mixtures-Molecules Ken Kroenlein Citrine Informatics Complex Substance Schemas: A Case Study Flyer: Available Here Recording: Available here Description: The IUPAC WorldFAIR Chemistry project organized the fourth webinar of the series titled “What is a Chemical?: Innovation in Chemical descriptions. The Webinar focused on creative approaches of chemical description, particularly those that address chemicals in complex systems: such as reactions, multiple-component systems/mixtures, complexes, composites, formulations, and using these in different computational settings, representation services, tools, and mechanisms. The webinar series highlighted the current status of working with descriptions of chemical substances, development of digital tools to transform chemical data notation into digital entities, and ways to implement FAIR (Findable, Accessible, Interoperable, Reusable) data principles across the chemical enterprise. The webinar lasted for about 90 min, and we had 5 invited guest speakers to present their perspectives within a 5 min flash presentation for each. The webinar was followed by a panel discussion. *IUPAC is the world authority on chemical nomenclature, terminology, and standardized methods of measurement, and is engaging in a concerted effort through collaboration with the broader chemistry and data science communities to translate a range of assets and activities into the digital domain. **WorldFAIR Chemistry is one of several case studies in the global WorldFAIR initiative directed by CODATA and the Research Data Alliance to connect diverse activities across disciplines and geographies. ***WorldFAIR “Global cooperation on FAIR data policy and practice” is funded by the EC HORIZON-WIDERA-2021-ERA-01-41 Coordination and Support Action under Grant Agreement No. 101058393. Take out Points and Notes: Find the shared notes attached Polls and Registration Statistics: Find the poll results attached Other Webinars in the Series: Webinar 01: "What is a chemical? Handling Chemical Data Across Disciplines" Webinar 02: “What is a chemical? Applying Chemical Data to Industrial Challenges” Webinar 03: “What is a chemical? User’ Perspectives on Digital Machine Readable Depictions"