Database mirroring and Replication can be work together and they are provide availability for the publication database. Database mirroring basically work in two copies of a single database that are rarlly use on different computers. If we have to given any time for a only one copy of the database is currently available to clients which is called as the principal database. Updates made by clients to the principal database are applied on the other copy of the database, known as the mirror database. Mirroring involves applying the transaction log from every insertion, update, or deletion made on the principal database onto the mirror database.