Possible Duplicate:
What is the difference between #include <filename> and #include “filename”?
What is the difference between angle bracket < >
and double quotes " "
while including header files in C++?
I mean which files are supposed to be included using eg: #include <QPushButton>
and which files are to be included using eg: #include "MyFile.h"
???
When you use angle brackets, the compiler searches for the file in the include path list. When you use double quotes, it first searches the current directory (i.e. the directory where the module being compiled is) and only then it'll search the include path list.
So, by convention, you use the angle brackets for standard includes and the double quotes for everything else. This ensures that in the (not recommended) case in which you have a local header with the same name as a standard header, the right one will be chosen in each case.
Source: Stackoverflow.com