xrumer database - profiles vs posting - what is the difference?

xrumer has a few link database files, what is the difference between them?

Profiles - puts content (usually just a naked link) on forum profile
Posting - posts some text content including link as a forum post, either to a new thread or an existing thread

Though I haven't used Xrumer for a fair amount of time so things may have changed...

Yes, you said it right above. Just Profiles bases, probably not spammed and the link from there will be good. But if you start to post there, the account will be deleted along with the profile and the link. A database Posting, most likely spammed and post there for no use. In general, it is best to collect their bases.