By moving this pawn forward
		
		 
	 
	
		
			White wants to protect his d-pawn
		
		 
	 
	
		
			This pawn seems to be not protected
		
		 
	 
	
		
			So Black can take it
		
		 
	 
	
		
			If so, White should bring the Queen here
		
		 
	 
	
		
			And win this Knight (for free)
		
		 
	 
	
		
			That’s why Black moves this Knight
		
		 
	 
	
		
			And White replies by bringing his Bishop here
		
		 
	 
	
		
			In order to protect this pawn
		
		