Let's see if I can clarify more for you (and hopefully
not confuse you!) by giving some examples.
For any website to be available to the public online you need two things. A domain name and webhosting. For example, the domain name for this site is selfstartersweeklytips.com and hosting is provided by a company such as hostgator (or one of many others)
This message board is attached to SSWT and was placed in a directory (or folder) and is served by the same hosting service. You can see the URL for the forum is
www.selfstartersweeklytips.com/forum
The rest of her website can be found by going to
www.selfstartersweeklytips.com
Lynn's blog could have been added to the same domain and hosting by adding another directory or folder called "blog" or "clicknewz," so it would have been
selfstartersweeklytips.com/clicknewz/
And she would have installed that blog through the same hosting account as SSWT
But instead, Lynn choose to get a different domain name for her blog:
clicknewz.com
And she installed the blog in the "root directory" of that domain through her hosting account. (so when you type in clicknewz.com you go to the blog; there isn't another directory such as clicknewz.com/blog). She may have used the same hosting company and account (for example, one like hostgator that allows you to host multiple domains/sites on the same account), the same hosting company but under a different account, or a completely different hosting company.
You probably don't want the blog in the root directory for an existing website (or one your are building). Whatever is set up in the root directory is what visitors will see when they type your domain name into a browser.
Multiple blogs can be added to the same domain/site by setting up multiple directories/folders. For example
clicknewz.com/blog1
clicknewz.com/blog2
clicknewz.com/blog3
(The folders can be named anything you want, like
clicknewz.com/pencils
clicknewz.com/pens
clicknewz.com/chocolate)
Does that help?