The paper discusses the interpretation of models used to estimate the fundamental ecological niche (FN) and species distributional areas. It outlines a formal basis for understanding these models, clarifying their use and interpretation. The FN is defined as the set of environmental conditions that a species can tolerate, while the realized niche (RN) is the subset of the FN where the species actually occurs, considering biotic interactions. The geographic distribution of a species is influenced by abiotic conditions, biotic interactions, dispersal abilities, and evolutionary adaptations. Two main approaches are used to model the FN: the mechanistic approach, which directly measures physiological responses to environmental factors, and the correlative approach, which uses species occurrence data and environmental variables to infer the FN. The correlative approach is more commonly used, as it relies on presence data and can be influenced by biotic interactions. However, it is important to distinguish between the FN, RN, and actual distribution (P), as they represent different aspects of a species' ecology and distribution. The paper highlights the importance of considering the overlap between the FN, RN, and actual distribution, as well as the role of absence data in modeling. It also discusses the limitations of current models and the need for careful interpretation of results. The paper concludes that while niche models can provide estimates of the FN, they should be interpreted with caution, as they may not always reflect the actual distribution of a species. The use of pseudoabsences and the inclusion of a priori knowledge in modeling are also discussed, emphasizing the need for rigorous validation and careful consideration of assumptions.The paper discusses the interpretation of models used to estimate the fundamental ecological niche (FN) and species distributional areas. It outlines a formal basis for understanding these models, clarifying their use and interpretation. The FN is defined as the set of environmental conditions that a species can tolerate, while the realized niche (RN) is the subset of the FN where the species actually occurs, considering biotic interactions. The geographic distribution of a species is influenced by abiotic conditions, biotic interactions, dispersal abilities, and evolutionary adaptations. Two main approaches are used to model the FN: the mechanistic approach, which directly measures physiological responses to environmental factors, and the correlative approach, which uses species occurrence data and environmental variables to infer the FN. The correlative approach is more commonly used, as it relies on presence data and can be influenced by biotic interactions. However, it is important to distinguish between the FN, RN, and actual distribution (P), as they represent different aspects of a species' ecology and distribution. The paper highlights the importance of considering the overlap between the FN, RN, and actual distribution, as well as the role of absence data in modeling. It also discusses the limitations of current models and the need for careful interpretation of results. The paper concludes that while niche models can provide estimates of the FN, they should be interpreted with caution, as they may not always reflect the actual distribution of a species. The use of pseudoabsences and the inclusion of a priori knowledge in modeling are also discussed, emphasizing the need for rigorous validation and careful consideration of assumptions.