A more thorough explanation:

Definition: A person's ancestry or relationship with another traced through the father.

The paternal line refers to the lineage or ancestry of a person that is traced through their father. It is a way of understanding a person's family history and connections to their paternal relatives.

Example: John is interested in learning about his family history. He decides to trace his paternal line by researching his father's ancestors and their descendants.

This example illustrates how John is using the concept of the paternal line to understand his family history. By tracing his father's ancestors, he can learn about his paternal relatives and their connections to each other.