Schematic cross section through the inner Orion Nebula, showing the different zones of SW interaction. Blue indicates SW material, red indicates photoionized nebular material, and green indicates atomic/molecular gas, with darker shading corresponding to qualitatively higher density within each region. Arrows show the approximate direction of gas flows, with sizes that roughly scale with the momentum flux. Shocks in the SW are shown by short-long-dashed lines, while the contact discontinuities are shown by dotted lines. The drawing does not represent any particular cut through the nebula, and is not exactly to scale, although the sizes in parsecs of some major features are marked. The observer is located off the bottom of the picture. The inset box shows a zoom of the central region.