Without the Microsoft Visual C++ 2015 Redistributable x64 package, you might encounter errors or issues while running certain applications. These errors can range from missing DLL files to application crashes.
Most modern software does not "carry" these files internally to keep the installation size small. Instead, they rely on the being present on the host computer. You likely have several versions installed (2010, 2013, 2015, etc.) because different programs require specific versions of these libraries to function. Key Features of the x64 Version microsoft visual c 2015 redistributable x64