The name WinMain is just a convention
Although the function
WinMain is documented in the Platform SDK, it’s not really part of the platform. Rather,
WinMain is the conventional name for the user-provided entry point to a Windows program.
The real entry point is in the C runtime library, which initializes the runtime, runs global constructors, and then calls your
WinMain function (or
wWinMain if you prefer a Unicode entry point).