What is a vCard and how do I read it? It popped up in a message from a friend and I don't know what it is. Please explain.
vCard is contact information in a standardized form, accepted by most applications that deal in people or contact information. It is transportable between systems of differing operating systems, because of its defined form, generally: Name, Address, Phone Number, Notes, etc.
In Android, the standard application to read this is called either
Contacts. If you open the application and find the activity menu about it, one of the allowed processes will probably accept the data through "Import".
If you received it attached to a message, possibly even the messaging app will allow the import to the correct place in your system. See if its activity menu allows some processing of the attachment, similarly "Import".