The Xfer service is installed as part of the Curator package. Typically the service is installed on a transform server alongside AME and XCode, although in some cases this may vary.

XFer is added and seen as a device within Device Director (typically added and seen as XFer Basic)
Once added to Device Director, this opens up for jobs to be sent to the Xfer Service to be carried out.

Xfer Basic handles jobs from Device Director which require the movement of files or copying files from one location to another.
With Curator, moving and copying files is necessary in many different areas, such as ingest, file delivery, or even archiving.

Looking at an Xfer Basic job, you will be able to see the input (where the file is originally) and the output (the destination) the job will also show the profile either being XFer Move or Xfer Copy, this shows if the Xfer service is going to move or copy the file.

Note that we also use Xfer with cloud services such as S3. In these cases, the Xfer service will need to call upon particular profiles which house the cloud credentials so that Xfer can perform the moves and copies, an example of this would be Xfer AWS S3.