The GroupBox. The GroupBox is a built-in control that allows you to group together a number of other controls. When you use the default styling for a GroupBox, the child controls are surrounded by a border that includes a caption. A GroupBox control is a container that adds a header and a border to the area that can be used to place other controls. The <GroupBox> XAML element and the GroupBox class in C# represents a group box control at design time and runtime respectively.
The GroupBox control is not an exciting control in the Windows Forms platform, but is certainly a useful one. It can help you organize a clean and usable interface for your program, and is helpful on preferences windows and dialogs.