What is crosstab chart?

A crosstab, also called a text table or pivot table, displays numbers as text in a grid of rows and columns rather than as a graphic.

You build one by putting dimensions on Rows and Columns and a measure on the Text target of the Marks card. Show Me lists it first, since it is what most fields will produce.

It is the right choice when people need to read exact values — reconciliation, financial reporting, anything that will be checked figure by figure. It is the wrong choice for spotting a pattern, which is what charts are for.

A middle path worth mentioning: a highlight table is a crosstab with colour applied to the cells, so you keep the precise numbers while making the shape of the data visible.