Rugby boots tend to be more substantial than soccer boots. The nature of the game is such that your feet are going to be stepped on a lot more often and the extra protection can be useful. In terms of the studs, rugby studs tend to be larger and longer. If you play in one of the tight five positions (props, hooker or second row) then you need real rugby boots to get sufficient traction for scruming, particularly if the pitch is the least bit wet. In my opinion, you can go either way for as a flanker or eightman, as traction in the scrum is less critical and mobility more important. Personally I know flankers who will use either type depending on conditions -- rugby studs in general conditions, but soccer ones if the pitch is especially hard and dry. They seem to get by The backs will vary as well. Centres tend to do more rucking then the other back positions -- they will tend to favour six-studded rugby boots. Scrumhalfs, flyhalfs and wingers will often use soccer boots for the extra mobility. Just be aware that if you go with soccer boots, the studs have to be of the molded plastic variety. The metal "blades" which you see on some boots are illegal on a rugby field.

The rugby ball is prolate spheroid shaped, while the soccer ball is round. In rugby, a goal is earned by kicking the ball over the bar, while in soccer it’s placing the ball into the net. Read more difference you got here:

Rugby boots favour grip over speed, and are made to handle muddy conditions While Football boots favour speed over grip, and are made for drier conditions

One is called rugby and the other is called soccer