What are annotations used for in Tableau?

Annotations in Tableau serve the purpose of adding notes or comments that provide context about specific data points or areas in a visualization. This feature allows users to highlight noteworthy insights or details directly within the visual itself, making it easier for others to understand the significance of the data presented. By incorporating annotations, you can clarify trends, provide additional information, or even pose questions about the data.

This capability enhances the storytelling aspect of data visualizations, as it allows the creator to convey important insights or observations directly to the audience, ensuring that key messages are not lost in the complexities of the data. The other choices do not accurately represent the function of annotations: summarizing large datasets pertains more to data aggregation techniques rather than visual commentary, automatic report generation involves different tools and features within Tableau, and filtering data pertains to data manipulation methods that are separate from the context-based annotations.