visual studio 2010 - Pragma comment C++ -

When I am using a non-standard library in C ++, then I need to add a library name in Linker - & Gt; Input - - & gt; Additional dependencies but write alternative

  #pragma comment (Lib, "Library name")   
 Are these two methods completely identical?   
 
 
 They are not.  
 It is said that pragma adds an  defaultlib  option to a compulsory lib for the linear line.  
 The latter does not matter what is processed, and if you are missing, you get the error. The original Lib is silently ignored if not found.    and use the option to "Ignore the default Libs" or "Ignore the specific default libs" that can be used to dismiss its use.