A heatmap is a visual representation of visitor interaction data — typically clicks, cursor movement, or scroll depth — overlaid on a webpage using color gradients, commonly warm colors for high activity and cool colors for low, to show where engagement is concentrated.
The three most common types measure different things: click heatmaps show where visitors actually clicked or tapped, move heatmaps track cursor movement as a rough proxy for visual attention, and scroll heatmaps show how far down a page visitors typically reach before leaving. Because heatmaps aggregate many visits into one composite image, they're good for spotting patterns that would be tedious to find by reviewing individual sessions one at a time.
A scroll heatmap on a long landing page might reveal that 90% of visitors reach the headline at the top but only 20% scroll far enough to see the pricing table near the bottom, suggesting the pricing information may need to move higher.
A click heatmap shows where visitors actually clicked or tapped, while a scroll heatmap shows how far down the page visitors typically scroll before leaving — they answer different questions about the same visit.
Not meaningfully — heatmaps are aggregate visualizations built from many visits combined; to see one specific visitor's behavior in detail, session replay is the more appropriate tool.
Generally the underlying concept is the same, but mobile heatmaps track taps and scroll instead of mouse movement, and are usually reported separately since layouts and interaction patterns differ significantly by device.