Jimu is the name of the framework for ArcGIS Experience Builder and it contains the following packages:
- jimu-arcgispackage contains classes and methods for working with the ArcGIS Maps SDK for JavaScript. Commonly used classes include- Jimuand- Map - View - Jimu.- Map - View - Component 
- jimu-corepackage provides the interfaces and types to work with widget props, message actions, data source, etc. It also defines several classes that will be used throughout your experiences.
- jimu-for-builderpackage provides classes for developing the widget setting page such as- Settingand- Change - Function - Widget.- Setting - Props 
- jimu-for-testpackage contains classes, types, and functions that can be used for unit testing.
- jimu-uipackage includes UI components to be used in your experiences. For performance reasons, the UI components are split into three categories. The- jimu-uientry contains the general UI components, such as- Button,- Input, etc. The entries under- jimu-ui/basiccontains focused components, such as- Colorand- Picker - QR. Entries under- Code - jimu-ui/advancedare heavy and complex, for example, the- setting-componentsentry contains several components that may be used in the widget setting.