Range is an object that represents a collection of rectangular areas or regions in the grid and helps in collective manipulation of the cells lying within the range. A new instance is created and returned by calling range method of the grid and its parameter is an object that takes at least one property and at the maximum 4 properties out of r1, c1, r2, c2, rc, cc where r1 is rowIndx of first row, c1 is colIndx of first column, r2 is rowIndx of last row, c2 is colIndx of last row, rc is row count or number of rows, cc is number of columns in the range.

var range = grid.range( { r1: 2 } ) to create range of single row.
var range = grid.range( { r1: 2, r2: 4 } ) to create range of 3 rows.
var range = grid.range( { r1: 2, rc: 2 } ) to create range of 2 rows.
var range = grid.range( { r1: 2, c1: 3 } ) to create range of single cell.
var range = grid.range( { c1: 2, c2: 4 } ) to create range of 3 columns.
var range = grid.range( { c1: 2, cc: 4 } ) to create range of 4 columns.
var range = grid.range( { r1: 2, c1: 2, r2: 5, c2: 4 } ) to create block range.

//setter
grid.range({r1:0, c1:0, rc:2, cc:2}).value(
[
    ['a', 1],
    ['b', 2]
]);

//getter
var val = grid.range({r1:0, c1:0, rc:2, cc:2}).value();

Selection is an object derived from Range and hence has all the methods of Range available to it. It is similar to Range except that every grid has only one instance of Selection object and this instance can be obtained by calling selection method of the grid where selection instance represents all the selected rows, cells and columns in a grid.

var selection = grid.selection().

The same instance is also available as ui property in the selectChange event that fires whenever there is a change in selection state of the grid.