What do heat maps primarily display?

Heat maps are particularly effective in visualizing the intensity or density of data in a specific area, rather than just showing the evolution of a metric over time. They display variations in data through color gradients, which makes it easy to identify patterns, trends, and concentrations within a dataset.

In the context of user engagement or behaviors, heat maps might illustrate the density of interactions within a specific area, such as website clicks or geographic regions where users are most active. The colors represent the intensity—darker or warmer colors usually indicate higher density, while lighter colors suggest less activity. This visual representation can provide immediate insights into user distribution and hotspots, helping businesses make informed decisions on resource allocation and targeted strategies.

The other options deal with different aspects of data visualization: usage over time tracks changes in user activity across time periods, the evolution of a metric focuses on trends rather than density, and performance levels of different servers measure operational effectiveness rather than visualizing user density.