The DevExpress ASP.NET Grid View (ASPxGridView) can automatically truncate cell values if they don't fit into cell width. To indicate that the text is clipped, the grid displays an ellipsis ('...').
By default, this functionality is disabled, set the AllowEllipsisInText property to true to enable it.
Resize grid columns to see this feature in action. Point the mouse cursor over an ellipsis to display a tooltip with the full text.