A cache group is a collection of Varnish Cache servers that have identical configuration. Attributes on a cache group includes:
A VCL file is a configuration file which describes control flow when Varnish Cache handles a HTTP request. VAC distributes and store VCL files for you.
A parameter set is a list of Varnish cache parameters. A parameter set can be applied to one or more cache groups simultaneously, as long as the cache groups all consist of cache servers of the same Varnish Cache version.
VAC ships with a JSON-based RESTful API. All actions performed via the user interface can be replicated with direct access to the API. This includes fetching all real-time graph data.
The default user is “vac” and the default password is “vac”. Please change the login password the first time you log in.
You can access VAC on http://server_hostname/ .
The VAC as three types of roles both for the UI and API.