How can I use custom error classes to improve error handling in a REST API?

Define custom error classes that inherit from a base error class. These classes can encapsulate specific error types and provide additional information (e.g., error codes, validation details). This improves code organization, readability, and allows for more specific error handling logic. Example: `class ValidationError extends Error { constructor(message, field) { super(message); this.field = field; } }`