| title | titleSuffix | description | author | ms.author | ms.date | ms.topic | ms.service |
|---|---|---|---|---|---|---|---|
What is an ontology? |
Azure Digital Twins |
Learn about digital twin ontologies, how they're used in Azure Digital Twins, and how these DTDL ontologies can be used for modeling in the context of certain industries. |
baanders |
baanders |
02/28/2022 |
conceptual |
digital-twins |
This article describes the concept of industry ontologies and how they can be used within the context of Azure Digital Twins.
The vocabulary of an Azure Digital Twins solution is defined using models, which describe the types of entities that exist in your environment. An ontology is a set of models for a given domain, like building structures, IoT systems, smart cities, energy grids, web content, and more.
Sometimes, when your solution is tied to a particular industry, it can be easier and more effective to start with a set of models for that industry that already exist, instead of authoring your own model set from scratch. This article explains more about using pre-existing industry ontologies for your Azure Digital Twins scenarios, including strategies for using the ontologies that are available today.
Ontologies provide a great starting point for digital twin solutions. They encompass a set of domain-specific models and relationships between entities for designing, creating, and parsing a digital twin graph. Ontologies enable solution developers to begin a digital twins solution from a proven starting point, and focus on solving business problems. The ontologies provided by Microsoft are also designed to be easily extensible, so that you can customize them for your solution.
Also, using these ontologies in your solutions can set them up for more seamless integration between different partners and vendors, because ontologies can provide a common vocabulary across solutions.
Because models in Azure Digital Twins are represented in Digital Twins Definition Language (DTDL), ontologies for use with Azure Digital Twins are also written in DTDL.
Here are some other benefits to using industry-standard DTDL ontologies as schemas for your twin graphs:
- Harmonization of software components, documentation, query libraries, and more
- Reduced investment in conceptual modeling and system development
- Easier data interoperability on a semantic level
- Best practice reuse, rather than starting from scratch
There are three possible strategies for integrating industry-standard ontologies with DTDL. You can pick the one that works best for you depending on your needs:
| Strategy | Description | Resources |
|---|---|---|
| Adopt | You can start your solution with an open-source DTDL ontology that has been built on widely adopted industry standards. You can either use these model-sets out-of-the-box, or extend them with your own additions for a customized solution. | Adopting industry standard ontologies Extending ontologies |
| Convert | If you already have existing models represented in another standard format, you can convert them to DTDL to use them with Azure Digital Twins. | Converting ontologies Extending ontologies |
| Author | You can always develop your own custom DTDL models from scratch, using any applicable industry standards as inspiration. | DTDL models |
No matter which strategy you choose for integrating an ontology into Azure Digital Twins, you can follow the complete path below to guide you through creating and uploading your ontology as DTDL models.
- Start by reviewing and understand DTDL modeling in Azure Digital Twins.
- Continue with your chosen ontology integration strategy from above: Adopt, Convert, or Author your models based on your ontology.
- If necessary, extend your ontology to customize it to your needs.
- Validate your models to verify they're working DTDL documents.
- Upload your finished models to Azure Digital Twins, using the APIs or a sample like the Azure Digital Twins model uploader.
Reading this series of articles will guide you in how to use your models in your Azure Digital Twins instance.
Tip
You can visualize the models in your ontology using the Azure Digital Twins Explorer or Azure Digital Twins Model Visualizer.
Read more about the strategies of adopting, converting, and authoring ontologies:
Or, learn about how models are used to create digital twins: Digital twins and the twin graph.