1) Repeater is template driven, DataGrid is rendered as Table.
2) Repeater cannot automatically generates columns from the data source, where as DataGrid can.
3) Repeater supports customizable row separator, where as DataGrid does not support this feature.
4) Sorting and Paging is only allowed in DataGrid but not in Repeater.
5) Selection of row is supported by DataGrid and not by Repeater.
6) Editing of contents is supported by DataGrid and not by Repeater.