Why did the Greek gods become Roman gods, change their names?

Roman culture was very strongly associated with Greek, if you look at architectural monuments or sculptures, you can see a lot of similar elements. We can say that both Greek and Roman culture had the same roots. The pantheon of gods was no exception. Although the Roman gods had different names, in fact they were the same personages as in Greek mythology. Examples: Greek god Zeus – Jupiter, Aphrodite – Venus, Ares – Mars, Poseidon – Neptune, etc.