You can export selected contacts and then import them on another computer. Or, export all your contacts so you have a backup copy of them.
Contacts are exported as a vCard file (.vcf). By default, notes and photos are included. To exclude them, choose Contacts > Preferences, click vCard, and then deselect the options.
Drag a contact, multiple contacts, or a group to the desktop.
You can also select contacts and choose File > Export > Export vCard.
Choose File > Export > Contacts Archive.
Choose a location, then click Save.
Save the archive file in a safe location, in case you need to restore all your contact info.
When you import contacts to an Exchange account, information that isn’t supported is added to the Notes field.