qmake is a UTILITY that automates the generation of Makefiles.

Makefiles are used by the program make to build executable programs from source code; therefore qmake is a make-makefile tool, or makemake for short.

QMake does not call g++/gcc directly. Instead, qmake creates native make files on your current platform. Under linux it creates standard GNU make files, under WINDOWS it can generate visual studio make files, under Mac OS X it can generate XCODE PROJECT files. You then invoke your native build SYSTEM (either GNU make, or MS NMake, or xcodebuild or whatever), which will call your native compiler (g++/gcc or whatever).

qmake is a utility that automates the generation of Makefiles.

Makefiles are used by the program make to build executable programs from source code; therefore qmake is a make-makefile tool, or makemake for short.

QMake does not call g++/gcc directly. Instead, qmake creates native make files on your current platform. Under linux it creates standard GNU make files, under windows it can generate visual studio make files, under Mac OS X it can generate XCode project files. You then invoke your native build system (either GNU make, or MS NMake, or xcodebuild or whatever), which will call your native compiler (g++/gcc or whatever).