Description: The heterogeneous graph theory studies graphs that contain different types of vertices and edges, allowing for the modeling of complex relationships in systems where elements are not homogeneous. Unlike homogeneous graphs, where all vertices and edges are of the same type, heterogeneous graphs can include, for example, nodes representing various entities such as individuals, organizations, or concepts, as well as edges indicating different types of relationships, such as interactions, associations, or hierarchies. This diversity in the graph structure allows for a richer and more accurate representation of information, facilitating data analysis in contexts where interactions are multifaceted. Heterogeneous graph theory builds on fundamental concepts of graph theory, such as connectivity, traversal, and centrality, but expands to address the additional complexity arising from heterogeneity. This makes it a valuable tool in fields such as data mining, machine learning, and bioinformatics, where relationships between different types of entities are crucial for gaining meaningful insights.