While it is easy to create a single plot — as demonstrated in Plots, Figures, and Glyphs — Bokeh also supports the construction of multi-faceted data visualization applications, potentially with multiple plots and a graphical user interface (GUI) containing multiple widgets to support user interaction with the data. In those situations, the ability to manipulate documents and layouts becomes an important ingredient.

Documents are a data structure for organizing Bokeh applications, and contain all the elements needed to render a visualization within a web browser. Documents also play an important role is disseminating Bokeh server applications to multiple, independent browser clients, as discussed in a later topic on Bokeh server.

Layouts comprise a collection of Bokeh objects, along with information about how those objects should be laid out and organized in the visualization application. Plots and widgets can be laid out in nested rows and columns, or grids, in order to present the desired GUI.

We will see some examples of documents and layouts in the topic on Bokeh server.