pcsx2-1.4.0-setup.exe - PCSX2 1.4.0 Standalone Installer - This is the PCSX2 1.4.0 full installer package for Windows.
pcsx2-1.4.0-source.zip - PCSX2 1.4.0 Source Code - This is the source code of the 1.4.0 release of PCSX2 and its plugins.
pcsx2-1.4.0-binaries.zip - PCSX2 1.4.0 Windows Binary - This is the PCSX2 1.4.0 compressed package for Windows (you need the Visual C++ 2015 x86 Redistributable for this version to work).