Importing and updating contacts
by 
To automate the import and update of contacts from one application to another.
Emails, SMS and voice messages
by
To automate the sending of messages between Digitaleo and your application.
What you can do with 
Synchronise your contacts unilaterally
For example: update a contact in ActiveCampaign when they unsubscribe from Digitaleo.
Automate your text messages, emails and voicemails
For example: send an email to a contact using Digitaleo when the contact is added to ActiveCampaign.