Creating beautiful Cards on your Boards is great, but nobody wants to keep their work to themselves! With all Boards, you have options to share!
By sharing a standard copy, the recipient will receive a Board that is the exact copy of what you have produced. Once shared, you the sender will have no access to the recipient's Board.
You can share as a copy with either read only or edit access.
Sharing as a 'Live' copy means that you, the Board creator, retain control over the Board that the recipient has on their Account. You may share with read only or with edit access, but any changes that are made will be reflected on all recipient's versions.
If you share with read only access, the recipient will have no ability to make any changes.
Granting edit access will mean that the recipient can make changes to existing Cards, add new Cards, whatever changes you can make, they'll be able to make!