What are differences between pipe and tube,Birmingham wire gauge,schedule number

Pipes and tubes are specified in terms of their diameter and wall thickness.

Pipes:

• Heavy walled
• Relatively large in diameter
• comes in moderate lengths (20 to 40 ft)
• Threading is possible
• Pipe walls are rough
• Lengths of pipes are joined by screwed, flanged and welded fittings
• Made by welding , casting, or piercing a billet in a piercing mill
• The wall thickness of the pipe is indicated using schedule number
• Size of the pipe is indicated as nominal diameter

Tubes:

• Thin walled
• Less diameter
• available in the form of coils also, several hundred meters
• Can not be threaded
• Tube walls are smooth
• These are joined by compression fittings, flare fittings, or soldered fittings
• These can be cold drawn
• Tube thickness is indicated using BWG (Birmingham wire gauge) 
• Size of the tube is indicated as outside diameter