Cross Cutting Concerns

In development, some functionality use at multiple points in the application and those are
called cross-cutting concerns. Mainly, the cross-cutting concerns are concept wise
separate from the application’s own business logic. But mainly used with the Business logic.
So, Separating such cross-cutting concerns from the application's main business logic is where the  Aspect Oriented Programming (AOP) getting included to work properly with separation.

AOP Help you to separate the Cross Cutting Concerns from the application's main Functionality.
You can consider Following as Cross Cuttings Concerns
1) Logging
2) Exceptional Handling
3) Transaction
4) Security