European and French roulette tables look almost the same. However, there is a slight difference in the French game which affects the return to player rate.
If a player loses an outside bet in the European version with the result of the 0, the bet is lost and the money gone. In the French version there is the La Partage rule, which means the player will get half his bet back.
Alternatively you can also choose to put your bet En Prison and make the same bet again. It is then locked and you would forfeit the bet if you lose again. Most online casinos only offer European versions and not the French.