iCloud: Export contact information as a vCard
You can export all of your contacts as a vCard, which is an easy way to back them up.
Select one or more contacts in the contacts list.
To select several adjacent contacts, click the first one, then Shift-click the last one. To select multiple nonadjacent contacts, Command-click them on a Mac or Control-click them on a Windows computer.
Choose Export vCard from the Action pop-up menu at the bottom of the contacts list.
If you select multiple contacts, Contacts exports a single vCard containing all of them.