What Is an Instance in Programming

In programming, an instance refers to a specific realization of a class. When you create an object from a class, that object is an instance of the class. Each instance has its own set of data and state, but it shares the structure and behavior defined by the class.

An instance is a tangible, operational version of the class it is based on. Each instance can hold unique values for its attributes (properties). Instances can use the methods (functions) defined in the class. Every instance occupies its own space in memory.

In most contexts, instance and object are used interchangeably. An object is the result of instantiating a class. An instance emphasizes the relationship between the object and the class it was created from.