A heat map (or heatmap) is a graphical representation of data where the individual values contained in a matrix are represented as colors.
Tableau tends to regard these as Highlight Tables, albeit Highlight Tables in Tableau also encode with text. Heat Maps in Tableau encode using colour AND size, and so are regarded as a little more abstract. Confused?!
In practise, a lot of “Heat maps” you see in Tableau are a bit of a manual hybrid, where users manually create a “Heat map” where encoding does not include size, in order to achieve a uniform grid of coloured data points.
The ever useful The Information Lab series on “Show Me How” has this video, narrated by Chris Love:
A second video is from Alight Analytics:
And a final, third example, is by DataChampions:
Carly Capitula again documents the interworks.com series of “Tableau Essentials”
The Information Lab video above, is supported by this “Show Me How” blog post:
edupristine.com shared this comprehensive guide:
Due to the vagaries of the first post, the workbooks included below are what I’d term “manual Heat maps”. The semantics aren’t too important – this is a chart type which is very effective when used appropriately.
Here’s one from Andy Kriebel:
And an example shared by Josh Tapley: