What is the difference between DAO and Repository patterns?

DAO is an abstraction of data persistence.
Repository is an abstraction of a collection of objects.

DAO would be considered closer to the database, often table-centric.
Repository would be considered closer to the Domain, dealing only in Aggregate Roots.

Repository could be implemented using DAO‘s, but you wouldn’t do the opposite.

Also, a Repository is generally a narrower interface. It should be simply a collection of objects, with a Get(id), Find(ISpecification), Add(Entity).

A method like Update is appropriate on a DAO, but not a Repository – when using a Repository, changes to entities would usually be tracked by separate UnitOfWork.

It does seem common to see implementations called a Repository that is really more of a DAO, and hence I think there is some confusion about the difference between them.

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