This chapterestablishes peacebuilding as a historically and theoretically evolving concept and practice. Peacebuilding already has prisms open to multiple understandings. Nevertheless, seeing peacebuilding as apolicy process enables us to comprehend that the whole idea and activity cannot be understood from one paradigm exclusively. It is a mixed activity, while still oriented to realizing an ultimate goal,"peace," which has multiple goals and serves multiple interests. Weprovide a comparative analysis of peacebuilding with existing IR theories.Weidentify both similarities and differences between peacebuilding as a policy paradigm and the various IR theories. We contend that the policy approach could complement other theories and further contribute to both academic and practical understandings of peacebuilding. It becomes clearthat peacebuilding is not only a static picture of the theoretical mosaic but a hybrid approachwithdynamic interactions among actors and theories.