OpenCV 3.x only contains one lib - opencv_world.lib?

By default, the binary version of OpenCV-3.x doesn't contain the separate libs like opencv_core.lib. Instead, these modules are integrated in opencv_world.lib, so you only need to link to it.

On the other hand, if you do want separate libs, i.e. uniform APIs with OpenCV-2.x, you can build it yourself using CMake by enable the libs that you want. Like

This will generate opencv_core.lib.

Or run cmake with -D BUILD_opencv_world=OFF key