Answer
The following list describes the order in which map elements are drawn.
Elements in Data View:
• Topmost: Graphics selection
• Clip border*
• Feature selection
• Map annotation
• Graphic objects**
• Layer labels
• Layers (raster or vector)
• Bottommost: Map background***
* Optional border symbol that can be used when clipping a data frame; see Data Frame Properties > Data Frame > Clip Options > Clip to shape > Border
** Drawn with Drawing tools or inserted from external sources.
*** Set in Data Frame Properties > Frame > Background
Elements in Layout View:
• Topmost: Snap guides
• Graphics selection
• Elements in the layout‡
• Snap grid
• Print margins
• Bottommost: Paper outline
‡ Data frame(s), map surround elements (legend, north arrow, etc.), and other graphics added to layout.