According to wikipedia:
An area chart or area graph displays graphically quantitive data. It is based on the line chart. The area between axis and line are commonly emphasized with colors, textures and hatchings. Commonly one compares with an area chart two or more quantities.
Andy Kriebel shared a post in August 2016 which showed how to combine line and area charts, join separate data sources and apply some clever formatting to create the look below:
This from Carly Capitula at Interworks delves into the differences between Continuous and Discrete data:
The Information Lab also published a post investigating that core concept of Continuous and Discrete data in area charts:
Andy Cotgreave created a nice area chart as part of the #MakeoverMonday initiative. He actively blogs about Tableau and the v10 workbook can be located and downloaded from Andy’s blog post here:
#MakeoverMonday is also the driver behind another nice examples of area chart. This is this from Chris Love: