A Ridgeline is a representation of the numeric values of a category in a hump-like structure. The humps arise along a horizontal line. This plot shows a bar-like structure instead of a hump when used as a histogram.
Why do you need it?
A ridgeline overlaps each other, which saves a lot of space when the data is large. This advantage leads to a disadvantage too, it may hide some useful data, because of overlapping. Due to this property, if the overlapping doesn’t affect its motive, then it’s the best alternative.
What kind of data you can visualize with it?
A Ridgeline is best suited to categorical-data with fewer categories. Assume you have a dataset of the value of rings. We want a categorical quality-representation per value-range like fair, good, premium, etc. on a scale, then undoubtedly it’s, one of the alternatives. This clearly shows if data has a clear pattern, then this plot is beneficial.