OK so I've been wondering this for a while now.  Is there a difference between any of these rails because I've heard the same rail being called all of these by different people.  Is there a "correct" term for that kinda rail or are they just called different names by different people?
				
			 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
	 
 
		 
 
		 
	 
 
		 
 
		 
 
		 
 
		 
	 
 
		 
 
		 
 
		 
	 
 
		 
 
		 
 
		 
 
		 
 
		