Apache Beam-什么是显示数据?

I'm going through the internals of apache beam. In the transforms folder, there's a folder for display. On going inside the folder there are various classes. But the package-info file doesn't has enough information. Hence, What's display data in apache beam?

On going through the java docs - https://beam.apache.org/releases/javadoc/2.4.0/org/apache/beam/sdk/transforms/display/DisplayData.html

I find a one liner saying - Static display data associated with a pipeline component. Display data is useful for pipeline runner UIs and diagnostic dashboards to display details about PTransforms that make up a pipeline.

那么,什么是显示数据以及如何理解显示数据的工作原理?