Most of the code we have written so far concerns configuring the grid to be displayed. Often, we will want the grid to do something in response to user input—interaction. One of the common interactions in a grid is to select or move the rows of data. Ext JS refers to this interaction and how it's handled as the "selection model". Let's see how to set up a selection model.
Ext JS grids delegate the monitoring of user interaction with the grids rows, cells, and columns to a separate selection model object. The selection model is used to determine how rows, columns, or cells are selected, and how many items can be selected at a time. This allows us to create listeners for these selection events, along with giving us a way to query which rows have been selected.
The built-in selection models are: