Farm group and publication reporting operate in the same way and have the same reports, where they differ is who can access them.
'Farm groups' allow multiple different organisations to have access to the group reports. This provides a way for farmers, advisors and organisations to work collectively e.g. for a catchment group.
'Publication reporting' is more appropriate when only one organisation needs to access and analysis the data e.g. a milk processor wanting to report on and compare all the farms that supply them.