Difference between Managers and Services in Confluence API

[Domenico Manzo_Actonic]

Working with Confluence API in some add-ons I've noticed that some functions available from "managers" and some from "services".
For example:
CommentService (https://docs.atlassian.com/confluence/6.3.4/com/atlassian/confluence/content/service/CommentService.html) and CommentManager (https://docs.atlassian.com/confluence/6.3.4/com/atlassian/confluence/pages/CommentManager.html)
LabelManager (https://docs.atlassian.com/confluence/6.3.4/com/atlassian/confluence/labels/LabelManager.html) and LabelsService (https://docs.atlassian.com/confluence/6.3.4/com/atlassian/confluence/labels/service/LabelsService.html)
and so on.
What is the point to divide API functions into managers and services? What is the main difference between them?

[Aleksandr Zuevich]

Hi Domenico,

Nice to meet you here :)

In my opinion Services are high level while Managers are low level. Services in their implementation use Managers and their methods.

[Domenico Manzo_Actonic]

Thanks @Aleksandr Zuevich!

It will be great to hear some explanation from Atlassian team too :)