If you simply download the results, you will get presented quite a lot of columns. (If you don't use the customized option where you can select what fields you wish to download, that is)
Here is a quick overview and short description of them (work in progress):
A consecutively numbered count per submission for this specific action
The submission ID, it is an unique identifier for every single webform submission. (Great for debugging if you pass it along!)
The time the form submission was saved.
If this is not 0, that means that the saved submission is just a draft and not a finished full entry. If the submission triggers any action (Payment, newsletter subscription, thank you emails,..) they won't have been fulfilled.
- IP Address
The IP-address from where the webform was submitted.
The user ID. This is just relevant if a dedicated user submitted the form. Else it will be empty.
Same as above. Most supporters don't have a user account, they are treated as "anonymous".
The url the supporter that submitted the form came from
- External referer
The external url that redirected the supporter to this form
- Form URL
The URL of the form where it actually got submitted
Tags for automatic segmentation, you can set them on the edit page of your action under Advanced settings.
- Entry URL
The URL the supporter first entered on your page in this session.
- Referring SID
If there is another submission referring that supporter, you can find out here
Another GET parameter, that's mostly not populated
This is different to the UID above and is a hash for the supporter database.
This is not the country field of your form, but where the supporter's browser says it is from
After this point, there will be a column for every field you have added to your form :-)