Use [name of internet search engine] to locate the documentation:
In the address the word "stats" means the Statistics Toolbox, so you know the toolbox without even opening the page. Also when you open that page the Contents on the left hand side look like this:
> All Products
> Statistics and Machine Learning Toolbox
> Descriptive Statistics and Visualization
> Descriptive Statistics
which also tell us that this function is in the Statistics toolbox.
