As the name suggests, this module in OTM mainly deals with technical configurations that can be done in OTM for various client specific requirements.

Contacts

Contact in OTM should be defined for any communication that you want to initiate from system to end users(via email, etc) or external systems(via integration, etc). Following are entities in OTM that would be associated to contact:
Users
External Systems
Locations
Service Providers
Involved Parties
Agent Notify Contact Actions