How to setup the jms multisite localhost environment

I can not understant in tutorial chapter 9.

We need to set the virtual host for to make the sub-domains.

Kindly assist me to solve this issue.

When working on a localhost, the browser does not send all the information to the server like this is the case when working on Internet.

In chapter 9, we have described a specific procedure that consists in adding the "_host_" parameter in the URL.
This parameter is used to enter the domain name that simulate any slave site.
It is mandatory that you don't have ANY slave site defined with a "localhost" URL.
You can put any value but never use "localhost" in any slave site definition.

For example:
Site ID = slave1
Domain = slave1

When you enter the URL, put
localhost/mytestsite/admininstrator/?_host_=http://slave1
where _host_ is the value of the domain that you defined in the slave site.

You can also enter and ignore the http://
localhost/mytestsite/admininstrator/?_host_=slave1

How to access the front end of the site.From above point you have mentioned the administrator section then how to access the slave site.

The same way, add the _host_ parameter.

localhost/mytestsite/?_host_=slave1