In this Perspective article, the reader is introduced to several theoretical methods of determining the exciton wave functions and the corresponding eigenenergies. The methods covered are either analytical, semianalytical, or numeric. All the details associated with the different methods are made explicit, thus allowing newcomers to do research on their own, without experiencing a steep learning curve. The Perspective starts with a variational method and ends with a simple semianalytical approach to solve the Bethe–Salpeter equation (BSE) in gapped 2D materials. For the first methods addressed in this Perspective, the authors focus on a single layer of hexagonal boron nitride (hBN) and of transition metal dichalcogenide (TMD), as these are exemplary materials in the field of 2D excitons. For explaining the Bethe–Salpeter method, the biased bilayer graphene, which presents a tunable bandgap is chosen. The system has the right amount of complexity (without being excessive). This allows the presentation of the solution in a context that can be easily generalized to more complex systems or to apply it to simpler models.

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Excitons in two‐dimensional materials have become an exciting research topic due to their peculiar interaction with the electromagnetic radiation and their observation at room temperature. In the literature, there are different approaches to deal with the calculation of the excitonic states and their electromagnetic response. In the Perspective article by Maurício F. C. Martins Quintela, Nuno M. R. Peres, and co‐workers (article number http://doi.wiley.com/10.1002/pssb.202200097), some of these approaches are reviewed.