What is a vCard
vCard serves as an electronic business card. It is a convenient way of exchanging personal information such as name, address, phone number, and e-mail address.

How to add a vCard in Microsoft Outlook
With Outlook, you can automatically convert a vCard that was received from an external source to an Outlook Contact record. If the vCard arrives as an e-mail attachment, you can double-click the vCard attachment and then click Save And Close to add it to your default Contact folder. Alternatively, you can create a Contact from a vCard by dragging it to the Contacts folder. 

How to add a vCard in Apple Mail
To add a vCard someone sends you to Address Book, double-click the vCard icon in the message.  Address Book opens and displays the new card.