The Executions page provides a detailed account of every Pipeline Execution that can be filtered by Pipeline, Status, Tag, or any other pipeline property. It provides an at-a-glance view of which pipelines have failed, where they’ve failed, and the error messages returned.
Clicking into an Execution will give you a detailed view of the Pipeline Stages , Tasks , Configuration , Inputs, Task Inputs, Task Outputs, Task execution logs, and the output JSON object from the execution.
The Output JSON view is very useful for identifying variables from one task to pass to another - see Variables in Pipelines
Nested executions are Pipeline Executions that have been run as part of the Pipeline Task within a parent Pipeline. By default they’re hidden from view in the Executions pane, however if you add the Show: Nested Executions filter to the view, you can identify them by the Comments section, and they will be tagged with the parent Execution ID.