Before delving into an overview of simulation methods to study crystal nucleation from multicomponent liquids, it is important to discuss the additional adjectives that qualify the nucleation process in the scientific literature and their meaning. This is essential to define the applicability domain of molecular simulation methods and to formulate appropriate research questions that could emerge when different nucleation processes and mechanistic hypotheses are being investigated. Figure summarises the different classes of nucleation discussed below and provides a sequence of considerations in order to determine an appropriate classification.