Nginx root vs alias

stackoverflow discussion

Configuration A:

location /suburl/ {
	root /var/www/folder/;
}

Configuration B:

location /suburl/ {
	alias /var/www/folder/;
}

In both configurations the url mywebsite.de/suburl/mypath/index.html will be translated to different paths on the server:

Configuration A:

/var/www/folder/suburl/mypath/index.html

Configuration B:

/var/www/suburl/mypath/index.html