Theoretical review, on the other hand, involves the analysis and synthesis of existing theories, concepts, and research findings in a particular field. It is based on the study of literature, rather than on the collection of new data. Theoretical reviews are often used to identify gaps in the literature, to develop new theories, or to provide a comprehensive overview of a particular research area.
In summary, empirical literature is based on the collection and analysis of new data, while theoretical review is based on the analysis and synthesis of existing literature. Empirical literature is often used to test or support theories, while theoretical reviews are often used to develop new theories or to identify gaps in the literature.