Nowadays, homotopy theory has changed unexpectedly yielding a conceptual framework for a variety of subjects. One of the basic ideas that lie in the core of homotopy theory is localization. Roughly speaking, a localization is given by the data \((C,W)\) where \(C\) is a category and \(W\) a subclass of morphisms which gives rise to a weaker notion of isomorphism in \(C\). In this talk, I will show how localizations intervene in the well-known construction of triangulated categories in homological algebra and topology. If time permits, we will discuss more powerful applications of this machinery, such as how it is related to descent for stacks and Verdier duality.