The “cmake-gui” executable is the CMake GUI. Project configuration settings may be specified interactively. Brief instructions are provided at the bottom of the window when the program is running.
CMake is a cross-platform build system generator. Projects specify their build process with platform-independent CMake listfiles included in each directory of a source tree with the name CMakeLists.txt. Users build a project by using CMake to generate a build system for a native tool on their platform.
from https://cmake.org/cmake/help/v3.0/manual/cmake-gui.1.html