src/platform/packages/shared/react/kibana_context/README.mdx
Kibana uses React Context to manage several global states. Those states have been divided into several reusable components in relevant packages.
ReactDOM.render).EuiThemeProvider, it uses Kibana services to ensure the EUI Theme is customized correctly.KibanaStyledComponentsThemeProvider - A styled components theme provider for Kibana. This package is supplied for compatibility with legacy code, but should not be used in new code.