The host name options are used for the HSTS, Redirect www and non-www addresses and Redirect this (old) domain name to the new one features of the .htaccess Maker. The base directory option is used even when all of the .htaccess Maker options are disabled; it's used for the Joomla SEF URL block which cannot be disabled.
As a result, if you transfer your site on a new host you MUST change these configuration parameters to reflect your new server configuration. Do note that this will not happen automatically, even if you are using Akeeba Backup to transfer the site. In fact, you must remove your .htaccess file, change this parameters and then let Admin Tools create a new .htaccess file before you can use your site's front-end.
System Configuration
This final section contains all the options which let the Web.Config Configuration Maker know some of the most basic information pertaining your site and which are used to create the rules for some of the options in the previous section.
Enter the site's domain name for secure (HTTPS)
connections. By default, Admin Tools assumes it is the same as
your site's domain, but you have to verify it as it may be
different on some hosts, especially on shared hosts. Do not use
the https:// prefix, just the domain name and path to your site.
For example, if the address is
https://www.example.com/joomla
then type in
www.example.com/joomla
.
Enter the site's domain name for regular (HTTP)
connections. By default, Admin Tools assumes it is the same as
the address you are connected to right now, but you have to
verify it. Do not use the http:// prefix, just the domain name
and path to your site. For example, if the address to your
site's root is http://www.example.com/joomla
then
type in www.example.com/joomla
.
This is the directory where your site is installed. For
example, if it is installed in a directory named
joomla
and you access it on a URL similar
to http://www.example.com/joomla
you have to type in
/joomla
in here. If your site is installed
on the root of your domain, please use a single forward slash
for this field: /