The GtkBox widget organizes child widgets into a rectangular area. The rectangular area of a GtkBox is organized into either a single row or a single column of child widgets depending upon the orientation. Thus, all children of a GtkBox are allocated one dimension in common, which is the height of a row, or the width of a column. GtkBox uses a notion of <emphasis>packing</emphasis>. Packing refers to adding widgets with reference to a particular position in a GtkContainer. For a GtkBox, there are two reference positions: the <emphasis>start</emphasis> and the <emphasis>end</emphasis> of the box. For a vertical GtkBox, the start is defined as the top of the box and the end is defined as the bottom. For a horizontal GtkBox the start is defined as the left side and the end is defined as the right side. Use repeated calls to gtk_box_pack_start() to pack widgets into a GtkBox from start to end. Use gtk_box_pack_end() to add widgets from end to start. You may intersperse these calls and add widgets from both ends of the same GtkBox. Because GtkBox is a GtkContainer, you may also use gtk_container_add() to insert widgets into the box, and they will be packed with the default values for GtkBox:expand and GtkBox:fill. Use gtk_container_remove() to remove widgets from the GtkBox. Use gtk_box_set_homogeneous() to specify whether or not all children of the GtkBox are forced to get the same amount of space. Use gtk_box_set_spacing() to determine how much space will be minimally placed between all children in the GtkBox. Note that spacing is added <emphasis>between</emphasis> the children, while padding added by gtk_box_pack_start() or gtk_box_pack_end() is added <emphasis>on either side</emphasis> of the widget it belongs to. Use gtk_box_reorder_child() to move a GtkBox child to a different place in the box. Use gtk_box_set_child_packing() to reset the GtkBox:expand, GtkBox:fill and GtkBox:padding child properties. Use gtk_box_query_child_packing() to query these fields. <note><para> Note that a single-row or single-column GtkGrid provides exactly the same functionality as GtkBox. </para></note>