As Dweller said, THE Show is open to everyone while CES is officially trade only. But some audiophiles attend, which isn't a bad thing. However, the show that's a lot more consumer friendly and easier to get around (the Venetian is a pain) is RMAF, which I strongly recommend for the general public. THE Show is at the Alexis Park only, with small shuttle buses to and from a relatively hidden location near the Venetian.
One more thing. If you didn't preregister for CES, admission is $200.