You can share your contacts with internal and external partners. Depending on the requirements, several methods can be applied.
The Global address book provides the contact data for all users. Each user can use those contacts.
To make additional contacts available for internal users, proceed as follows:
Create a new personal or public folder where you can copy or move the wanted contacts to.
Share this folder with all or certain users.
You can also share an existing folder with read or write permissions. Further information can be found in Permissions.
If another user shared a contact folder with you, you can use those contacts. Further information can be found in Permissions.