What is meant by comparing texts by their purpose?

Comparing texts by their purpose involves analyzing how different texts aim to achieve similar goals or convey particular messages. This approach examines the intent behind each text, such as to inform, persuade, entertain, or instruct, and how effectively they accomplish that intent. By focusing on purpose, readers can gain insights into the choices authors make, such as tone, style, and structure, and how these choices align with their intended audience. Ultimately, this comparison enhances understanding of the texts' impact and significance in their respective contexts.