2015-12-08 10:00 PM
An initiator is a piece of software installed on a host/server that allows you to connect to your storage via network. An initiator group typically is where you would add the information of your host/servers initiator to grant access to volumes or LUNs. In Other words, Initiator is a member of the initiator group, initiator group is used to grant access to a volume or group of volumes.Once the Lun/Volume is online on the host you can assign any drive letter of our choice.
Check the following Link for more information on mapping.
Hope this helps.