The concern is the behavior we want to have in a particular module of an application. It can be defined as a functionality we want to implement.
The cross-cutting concern is a concern which is applicable throughout the application. This affects the entire application. For example, logging, security and data transfer are the concerns needed in almost every module of an application, thus they are the cross-cutting concerns.
Hope this helps!
Enroll in Spring course online to learn more about it.