As I understand it, Repository pattern is basically a generalization of the Data Access Object (DAO) pattern, and sometimes treated synonymously.
The way I mean it and implement it, is basically for each entity have a separate class to provide the database access. E.g. you have a Person (not complex at all, simply a value object) and a PersonRepository to get, update, and delete Person objects.
Then based on the complexity and scope of the project, Person either 1-to-1 maps to a e.g. a database table or stored object/document, or it is a somewhat more complex object in the business domain and the repository could be doing a little bit more work to fetch and construct it (e.g. perhaps some joins or more than 1 query for some data).