In computer science, in an object-oriented program, groups of objects form a network through their relationships with each other, either through a direct reference to another object or through a chain of intermediate references.
Unlike a normal data model such as a Unified Modeling Language (UML) class diagram, which details the relationships between classes, the object graph relates their instances.
Object-oriented applications contain complex webs of interrelated objects.
When stored in RAM, objects occupy different segments of the memory with their attributes and function table, while relationships are represented by pointers or a different type of global handler in higher-level languages.
For instance, a Car class can compose a Wheel one.