Which of the following is a key function of datasets in Power BI?

Datasets in Power BI serve a fundamental role by storing, organizing, and manipulating imported data. This allows users to prepare their data for analysis, ensuring that it is structured in a way that supports effective visualization and reporting.

When data is imported into Power BI, it often requires cleaning and transformation to meet the needs of the analysis. Datasets are designed to handle these tasks, providing a framework for data management such as merging tables, filtering data, creating relationships between different datasets, and defining measures or calculated columns. This preparation is essential because it enables users to derive meaningful insights from their data and ensures that the visualizations created from this data are accurate and relevant.

While datasets can contribute to real-time data visualization, that is not their primary function; this aspect is more about the dashboards and reports where visual representations are made. A dataset can link to external databases, but this is not its sole purpose, as datasets can also be built from various sources, including uploaded files or models created within Power BI. Furthermore, summarizing data in charts and graphs is a visual aspect that happens after the dataset is created rather than being an inherent function of the datasets themselves. Thus, the core function of datasets is their role in organizing and preparing the data for analysis.