Which is the best tool to quickly visualize data that answers a specific question without saving or sharing it?

Explorer is the best tool for quickly visualizing data to answer a specific question without saving or sharing. It's designed for ad-hoc analysis, allowing you to connect to data, create charts, and experiment with visualizations on the fly. You can quickly iterate through different chart types and metrics to gain insights without the overhead of creating a full report. Data sources define the connection to your data but don't provide visualization capabilities. The Report Gallery and Templates are for creating and sharing full reports, which is more involved than a quick, unsaved visualization.