Difference between 2 competions and 2 organisation.
 

Does somebody know the specific difference between the IWWF and WWa?

And also between the world championship in Italy and the world championships in indianapolis?

Yes. Support WWA.

IWWF is the "official" governing body that the IOC would consider if and when considering wakeboarding/waterskiing for the Olympics. It's National chapter is USAWB, and affiliate of USAWS. They are still not even half as good with their competitions and representation of wakeboarding as WWA, but somehow got the recognition from IOC over WWA, likely because they have worked for decades to get waterskiing into the Olympics with no success, and now the Olympics are looking for a similar effect to what snowboarding has done for the Winter Olympics, and looking to "alternative" sports. IWWF does not look out for the best interest of the sport, they people who have been in charge in the past rarely even attended the events (although they would go to the host country and wine and dine themselves), and have more or less pushed themselves into wakeboarding because they realized there was $$ and opportunity in it. WWA has been supporting wakeboarding since day 1, and continues to do so, and is more by riders for riders. They know what's going on in the sport, and growing it, and unfortunately IWWF just has to use them as a model for what to do to do it right, half heart it, and get IOC credit. The good thing about having 2 bodies is more competitions, more opportunities, etc, however if and when cable wakeboarding makes it to the Olympics you will see a huge shift in riders going to more IWWF events, where now the majority of riders don't even consider them, although more have begun to the past year or so, likely because of the opportunity.

WWA is there for you, IWWF is more there for themselves.

They're just different associations. Different countries choose to go to them and they're judged differently. The WWA title is more serious though as more pro's go to it. Like at Italy this year there was harley, adkinson, powers, prideaux, wing, nick jones, merett.... but no one like soven, rusty, errington etc. I think the WWA is more dominated by the US and surrounding countries.

/\ and also kinda what A-dub is saying yeah. The general vibe I've gotten is that the IWWF is run by water-skiiers and don't put too much emphasis on wakeboarding. The events are never really great and people (including someone I ride with frequently) can get screwed over with the judging (As in a-fall-isn't-as-bad-as-casing-the-wake kinda screwed over) I was at the WWA in spain in 04 and at Italy in July and even though it was 7 years ago the WWA was better. In the IWSF there's no cash prizes and Italy didn't have great sponsors (Fanta, Durex, Kia but nothing like the Miss. Reef contest) and for prizes they got Snowboards...... yes snowboards

/\ and also kinda what A-dub is saying yeah. The general vibe I've gotten is that the IWWF is run by water-skiiers and don't put too much emphasis on wakeboarding. The events are never really great and people (including someone I ride with frequently) can get screwed over with the judging (As in a-fall-isn't-as-bad-as-casing-the-wake kinda screwed over) I was at the WWA in spain in 04 and at Italy in July and even though it was 7 years ago the WWA was better. In the IWSF there's no cash prizes and Italy didn't have great sponsors (Fanta, Durex, Kia but nothing like the Miss. Reef contest) and for prizes they got Snowboards...... yes snowboards

(thats meant to be its better to fall than to case the wake)

But does it looks to me that the iwwf is organize events over the world and wwa more in the usa only, cause i'm from Belgium?

likely because that is a requirement for the IOC, not because they want to. Have to have so many competitions in so many countries for the IOC to consider the sport....

wich world championship can be concluded as the only real one?

WWA Worlds...

One of the Major Differences is that WWA events are run by full time staff who earn their living as part of the organization.

USA Waterski/Wakeboard and IWWF events are run mostly by people who are not paid and are doing the work for the enjoyment of the sport and giving back to the community (USA wakeboard). USA Waterski/Wakeboard for example helps host a large number of grassroots events, prior to this years WWA and INT joining, the WWA did not do grassroots events.

IWWF is a newer organization in terms of wakeboard acceptance, I believe the name change was in early 2010 or late 2009, While the WWA has been operating for over 20 years. As with any organization there is a building period and finding their place in the sport.

WWA has really shown that they are about supporting the high level athletes as a subjective sport while IWWF treats it more objectively, as nearly any organization that attempts to gain acceptance from the International Olympic Committee would.

I am one of the people who contributes as much as I can to USA Wakeboard and the WWA. I compete in both and organize for USA Wakeboard, and have tried to mimic some of the WWA event styles. I can honestly say that organizing as high quality of events as the WWA does would not be possible without the help of full time employees. The turnover that USA sees is because our livelihoods come from other fields or professions. Ideally the two organizations would never be in conflict but differing ideals and visions of the sport always complicate that ideal.