What is the purpose of attributes in programming or system modeling?

In programming and system modeling, attributes are used to add metadata to classes, methods, properties, or other code elements. They allow for describing additional information that can be used during compilation, execution, or for documentation generation.

In C#, attributes are applied using square brackets and can influence the program's behavior, for example:

• Managing object serialization.
• Setting validation rules.
• Marking methods for testing.

Example:

[Serializable]
public class User {
    [Required]
    public string Name { get; set; }
}

Here, the [Serializable] attribute indicates that the class can be serialized, and [Required] specifies that the Name property must be filled.

Thus, attributes help make the code more expressive and manageable without changing its logic.