Box Plots show summary information for data – the box shows the median and quartiles and the whiskers are extended to all points which are not outliers.
A very clear description for younger students can be found on BBC Bitesize. For A Level Students the Centre for Innovation in Mathematics Teaching includes Box Plots in Chapter 3 of their Statistics text (page 26 of the pdf file, which is page 76 of the text).
Box Plots are particularly useful when comparing one or more distributions;
Note that it is possible to display points with Box Plots in Plotly, the following data and charts demonstrates skew well:
You can learn more about Plotly for graphing and sharing your data here: Learn and explore Plotly