IFR means you're adhering to a certain set of rules (instrument ones). You could fly an entire IFR flight in glorious sunshine (IFR in VMC). But if you had to, you'd go into cloud (IFR in IMC), fly using your instruments panel, and land using the ILS.
VFR,you can't go into IMC. Gotta stay VMC. And obey the Visual Flight Rules.