A wall is a structure that defines an area, carries a load; provides security, shelter, or soundproofing; or is decorative. There are many kinds of walls, including:

• Walls in buildings that form a fundamental part of the superstructure or separate interior rooms, sometimes for fire safety
• Border barriers between countries
• Brick walls
• Defensive walls in fortifications
• Doors, mobile walls on hinges which open to form a gateway
• Glass walls (only when most of the wall, in smaller amounts it is called a window)
• Permanent, solid fences
• Precast walls
• Retaining walls, which hold back dirt, stone, water, or noise sound
• Stone walls
• Walls that protect from oceans (seawalls) or rivers (levees)

Description sourced from Wikipedia. Images sourced from Wikipedia.