While defining the settings of a node, you can use data (event parameters) received in the preceding nodes in a diagram. This enables inserting dynamic values (for example, a customer's name or ID) in the input of the following nodes in a workflow or a request in a webhook. Such reuse in workflows is called the event context.
The complete documentation, instructions, and examples are available in "Event parameters" section in Automation inserts.
If you're not familiar with the Automation-related terms, check them in the dictionary.