There's 2 different philosophies with these websites: * One world tree where each person only appears once and all users contribute to collect as much details

There's 2 different philosophies with these websites: * One world tree where each person only appears once and all users contribute to collect as much details (usually with supporting documents) as possible for each person in the tree. Some genealogists hate these as they either don't want to share their (often costly) research with everyone for free or they had bad experiences with some users changing seemingly correct details to something else without providing proof. * Several user-specific trees where each user has his own tree and can share it with selected other users or not. This also means that you might miss some details someone else found out about your tree's people. Those websites usually want a member fee for you to be able to see other user's trees and merge details from them. These are the sites I know of: * MyHeritage (user-specific trees) - very well known in Europe due to their excessive TV marketing, basically the gateway drug to genealogy here. But also lots of users that only tried it out once and thus have a very small tree only going back 1 or 2 generations. MyHeritage also matches your data with historic records and trees from other websites but wants to see money for you to manage those matches or copy details from other users' trees. * Ancestry (user-specific trees) - never tried that one but I've heard they have one of the largest collection of scanned (by them) and indexed historic records and are a big preference amongst genealogists. * FamilyTree (user-specific trees) - never tried that one * FamilySearch (one-world tree) - see the other comments - it's a great resource and they even have an API (e.g. Synium's MacFamilyTree/MobileFamilyTree can sync data with FamilySearch). And it's free. * WikiTree (one-world tree) - this free site "only" lets you build your tree but doesn't provide any own historic records. However, since users are encouraged to upload their records/proof and link those to their ancestors, you often find something. WikiTree also regularly has "competitions" where users are supposed to fill in details and climb to the top of the roster. Compared to all other sites the "Wiki" in "WikiTree" means that - apart from basic details like name and DOB/DOD - there's only a huge text field where you're supposed to add details in text form - like on a wiki page. If you use FamilySearch AND WikiTree, You can link your WikiTree data to FamilySearch and vice versa so it's clear those are the same person. The records also are publicly visible and appear on Google. Due to this I've been contacted by a few relatives I never knew about. So for your research - apart from searching FamilySearch or visiting one of their research centres - I'd also suggest making free accounts at e.g. MyHeritage and/or Ancestry and add all the things you know, then wait whether a match pops up. If you're unsure about a date, make sure to set it to "Estimated" or "About" so the matching engine doesn't try to find an exact match.