Metadata is information (data) about information. Metadata might be visible to your audiences, or only seen by systems like social media applications and search engines.
In the context of Sector, metadata can refer to HTML metadata, metadata used to support searches or filtered views, and system metadata that helps to identify and govern your content.
HTML metadata is read by bots and search engine crawlers. It helps search engines to understand and display your content in search results - learn more on Google's help page - 'Help Google (and users) understand your content'. HTML metadata is also relevant to sharing your content on social media platforms, as it can be used in link previews for your content.
Metadata in taxonomies
In Sector, metadata to organise and govern content is stored in Drupal taxonomies. The taxonomies are used as filter criteria and to label content - as well as for some magic behind the scenes. The guide Introduction to taxonomies explains which metadata is held in which taxonomy and how it is used. To learn how to manage taxonomies, see Managing taxonomies.