In 3D printing, "walls" refer to the outer layers of a printed object that provide its shape and structural integrity.
Adjusting wall settings can significantly affect layer adhesion, strength, appearance and print time of your model.

• Wall loops
• Alternate extra wall
• Detect thin wall

Mode: Simple.
Variable: wall_loops.
Type: Integer.
CLI Example: --wall-loops=1.
"Wall loops" is the number of walls printed on each layer.
Increasing the wall loops will:

• Enhance:
  • Layer adhesion
  • Strength
  • Rigidity
• Reduce infill ghosting
• Increase print time

Mode: Advanced.
Variable: alternate_extra_wall.
Type: Boolean.
CLI Example: --alternate-extra-wall=1.
This setting adds an extra wall to every other layer. This way the infill gets wedged vertically between the walls, resulting in stronger prints.
This option doesn't work well when Ensure vertical shell thickness is set to All; when both are enabled, OrcaSlicer offers to change it to Moderate.

Mode: Advanced.
Variable: detect_thin_wall.
Type: Boolean.
CLI Example: --detect-thin-wall=1.
By default, walls are printed as closed loops. When a wall is too thin to contain two line widths, enabling "Detect thin walls" prints it as a single extrusion line.
Thin walls printed this way may have reduced surface quality and strength because they are not closed loops.

• In small details, it can generate features that wouldn't be possible with traditional wall generation methods.
  
• In large prints, it can generate defects more easily due to the reduced wall thickness.