These functions are used to create and destroy cursors. There is a number of standard cursors, but it is also possible to construct new cursors from pixbufs. There may be limitations as to what kinds of cursors can be constructed on a given display, see gdk_display_supports_cursor_alpha(), gdk_display_supports_cursor_color(), gdk_display_get_default_cursor_size() and gdk_display_get_maximal_cursor_size().