Are you getting confused and over-whelmed by the growing number of websites that make use of the ability for family members to share in the research and construction of family trees?
This type of resource is relatively new to the Internet, and is usually billed under the heading of a "Web 2.0" capability. In a nut shell, such sites allow you to collaborate in your research with whoever you give permission to join you. You and your invitees will have joint access to the data you post on the website so you can all edit it and add to it. The mechanism allows for true collaboration. Of course you have to be careful about who you give permission to do this to your data, but if we are talking about fellow family researchers, there usually is not a problem.
There are a growing number of such sites and you may recognize names such as Kincafe, OurStory, and WeRelate. My trouble is that after I hear about a few of them, they sort of all run together in my mind. There is a website that can help to keep them straight, however. It gives a short description of the major players in the field and hot links to each of them.
You can find the site at: http://genealogy.about.com/od/social_networking/