This chapter focuses on the main theoretical concepts derived from descriptive studies: translation shifts, systems and polysystems, assumed translations, target-side priority, norms, universals, laws of translation, and insights from process studies. Translation shifts are patterned differences between translations and their start texts. They can be analyzed top-down or bottom-up. Translations play a role in the development of cultural systems. Translations can be studied as facts of a target culture, as opposed to the start-culture context that is predominant in the equivalence paradigm. The translator identifies the function of the form in the start-language tradition, and then finds the corresponding function in the target-language tradition. Some proposed "universals of translation" describe the ways in which translations tend to differ from non-translations. Some tentative "laws of translation" describe how translations tend to correlate with relations between cultures. Comparative descriptions of the cognitive processes of novice and experienced translators can indicate what translators should be trained in.