Description: The term ‘orthologous’ refers to the evolutionary relationship between genes in different species that have evolved from a common ancestral gene through speciation processes. This concept is fundamental in the field of bioinformatics, as it allows researchers to trace the evolution of genes and proteins over time, providing valuable information about the function and adaptation of organisms. Orthologous genes imply that, despite species divergence, orthologous genes maintain similarities in their sequence and function, suggesting they have preserved essential biological roles throughout evolution. This phenomenon is crucial for understanding how genetic variations can influence the phenotypic characteristics of organisms and how these variations can be selected in different environments. Identifying orthologous genes is a powerful tool in genetic research, as it allows scientists to infer gene functions in less-studied species based on their homology with model species’ genes. In summary, orthology is a key concept in bioinformatics that helps unravel the complexity of genetic evolution and its impact on biodiversity.