# ESDL concepts

This chapter describes the ESDL concept. The following topics will be covered:

* [Design principles](https://energytransition.gitbook.io/esdl/esdl-concepts/design-principles): the general design principles behind the language: capabilities and aggregation
* [Energy System structure](https://energytransition.gitbook.io/esdl/esdl-concepts/energy-system-structure): the high level structure of an EnergySystem description
* [Data types](https://energytransition.gitbook.io/esdl/esdl-concepts/data-types): the most important data types in the language: EnergySystem, Instance, Potential, Area, Asset, EnergyAsset, Port, Profile
* [ESDL model](https://energytransition.gitbook.io/esdl/esdl-concepts/esdl-model): a visualization of the ESDL model