If you have been around genealogy any time at all - you've heard this term - GEDCOM. A GEDCOM is a standardized file format specification that allows different genealogical software to share data. You can import your own GEDCOM into your new genealogical software when you are getting started and you can share your gedcom with someone who you want to have all of your info (such as a cousin). The GEDCOM manages the basic info very well. It is also being using by companies and genealogical sites - where you are encouraged to "Upload your GEDCOM".
There are advantages and disadvantages to "uploading your GEDCOM". The biggest advantage is that it is a quick and accurate way of sharing your information. However, this procedure requires you to understand the process well enough to export a GEDCOM from your genealogical software and then import that GEDCOM into the receiving site. You may not want to share all of your information - as your reason for sharing may only cover a part of your detailed info that you worked so hard to collect. And - you have to be sure that you can replace your GEDCOM if you discover there is an error - as there is nothing worse than sharing info in a public place and then discovering that you can't remove, edit or replace it.
Here are my basic approach:
1. Make sure that I want to share my information with this person/site. (do I trust them to use it as I expect? Have they commited to how they will use the information?)
2. Decide how much and which information I want to share (Do I want to share everything? If so, it's a bit easier, as I can export all of my info into one GEDCOM and then send/upload it. However - if I want to limit the information, then I need to export only a portion of my information)
3. Go through the procedure of exporting a GEDCOM - either with full or partial info. (This can be complicated - so plan on spending some time and reading your software HELP guide to figure out how to do this)
4. Test your GEDCOM. (This seems like extra work - but can save a lot of grief. I use the free LDS sofftware for this - as I can import the GEDCOM into PAF (Personal Ancestral File) and see exactly what I will be sharing. Note - there are tricks to this, too - as you will need to create a PAF file with your PAF software before you import the GEDCOM)
5. Finally - upload or send your GEDCOM (having thought out what you want to share and making sure that you are only sharing th epart you intend))
I hope this thought process will help you with this important procedure (and that you can find the technical guidance you need in order to do what you want)
One place that I do encourage you to "Upload your GEDCOM" is at Family Tree DNA - where it will help you and the researchers you match see your paper trail.