The number of potential values for continuous fields is impossible to anticipate.For example, if you have a field named , Tableau automatically aggregates that value as SUM (which you would then immediately change to AVG, because it's more logical to average grades than to add them), and that would then create a sixth value (3.02) that didn't exist until you added the field to the view. The number of potential values is, if not infinite, then certainly immense. Continuous means "forming an unbroken whole, without interruption"; discrete means "individually separate and distinct." In Tableau, fields can be either continuous or discrete.
While there are value labels on a continuous axis (0, 0.5, ...(Because such values are never aggregated, no new field values are created as you work with your view, so there is no need for an axis). We know that the field is continuous because of the axis and because the background is green.If a field is continuous, the background color is green. We know that it is a dimension because it is not aggregated.On the right, you see a view where that view has been further modified by clicking shelf, Tableau prompts you to choose which "members" of the discrete field to include in the view.3.0 in the following image), actual marks don't have to align with these labels as they would with column headers.
For example, in the following image, the blue bar actually extends to a value of 6.940 on the horizontal axis, not 7.0 exactly.