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When designing classes and objects, it is important to consider the following aspects:

1. Responsibilities: Each class should have a clear set of responsibilities and should represent a single entity or concept in the system. For example, in a banking system, we can have classes like Account, Transaction, and Customer.

2. Attributes: Classes have attributes that represent the state or data associated with the objects. Attributes can be defined as properties or variables within a class. For example, the Account class can have attributes like accountNumber, balance, and customerName.

3. Methods: Methods define the behavior or actions that objects of a class can perform. They encapsulate the logic and functionality related to the class. For example, the Account class can have methods like deposit(amount), withdraw(amount), and getBalance().

4. Relationships: Classes can have relationships with each other, such as associations, aggregations, or inheritances. These relationships define how objects interact with each other and can be represented using UML diagrams. For example, the Customer class can have an aggregation relationship with the Account class.

In designing classes and objects, each class should have a clear set of _ that represent a single entity or concept in the system.