Gatsby Admin enables non-developers to configure their sites
Gatsby Admin is an interface to configure your Gatsby site, including pages, layouts, plugin and theme management, theme file shadowing, GraphQL, and more. (Gatsby Admin RFC)
At the moment for users to configure their Gatsby sites they have to edit code (the gatsby-config.js file). Apart from that requiring some knowledge of coding, we can also create better experiences for e.g. using themes.