What is Aspect-Oriented Programming (AOP), and what problem does it solve?

AOP (Aspect-Oriented Programming)

AOP is a programming paradigm that lets you modularize cross-cutting concerns — behavior that would otherwise be duplicated across many unrelated classes, like logging, transaction management, or security checks — into a single reusable unit (an aspect), which is then applied declaratively to the relevant methods without scattering that code throughout the business logic itself.