In essence, yes. Being on a space station in orbit basically IS falling due to gravity, it's just that the astronaut and the space station keep missing the Earth due to constantly moving sideways so they never hit the/fall on the Earth. But they basically ARE falling.
Our bodies can't tell the difference, because all your body parts are accelerating and moving at the same rate, they're not in any tension in relation to each other so it's like there's no force, none that you, the person, can feel anyway.
There are some minor differences, tidal forces, but these effects are minor unless you're orbiting near a black hole etc. Tidal forces: slightly stronger gravity near the gravity source, so your feet, for example, are pulled sightly stronger, but these effects are minor usually. Astronauts on the ISS certainly don't feel it.
The term "zero-g" just means you don't feel any gravity, not that there isn't any. Of course, if you were in the void, far far far away from any gravity source, you would still be in "zero-g" because you wouldn't feel any... because there is none.
"g" here refers to a thing called "gravitational acceleration on Earth" btw, which is $g=9.81\:\rm m/s^2$. Fighter pilots go through 5g and more because they accelerate a lot... gravitation itself being irrelevant here, it's all about the felt acceleration itself. Emphasis on felt. Astronauts accelerate too, as I've said, but they, the persons, don't feel it, because they aren't squished onto anything, like the fighter pilots are squished onto their jet engines.