Installation

I hope this is not a stupid question.
I have installed and uninstalled GRAV three times, and still don't understand the mechanics of it. I use Mac and inmotion. What I don't understand is:
"Extract the zip file into your webroot
Point your browser at your local webserver: http://yoursite.com"

where and what exactly is my webroot
and how do I point my browser at my webserver.

I ask this because I cannot figure out how to write/edit on my desktop with my markdown program (Macdown) I can edit pages inside GRAV, not good, in fact not good at all, but I dont' understand this basic install so I am comfortable with it

If you have the site on a web hosting provider, they will tell you where to put the files to be shown on the site.

Otherwise, if you use MAMP then you have a setting that says where is your document root, where it will find the sites to serve.

So if you create a "www" folder in your home folder, you'll point MAMP to timbonner/www and inside that you'll unzip the Grav site, under timbonner/www/grav. Now start MAMP and you'll reach your site with http://localhost:8080/grav (if your port number is 8080, this is a MAMP setting)

You can use any editor you want to edit the markdown files. Just navigate to them using the Finder.