What is ndm and hdm expressing relationship in dbms?

Answer 1

NDM (Network Data Model) and HDM (Hierarchical Data Model) are two types of database models used in DBMS. NDM organizes data in a graph structure, allowing for complex relationships and many-to-many connections, while HDM arranges data in a tree-like structure with a strict parent-child hierarchy. Both models represent data relationships but differ in their organization and access methods, with NDM offering more flexibility in relationships compared to the more rigid structure of HDM.