Aspect-oriented programming(AOP) as the name suggests uses aspects in programming. It can be defined as the breaking of code into different modules, also known as modularisation, where the aspect is the key unit of modularity. Aspects enable the implementation of crosscutting concerns such as transaction, logging not central to business logic without cluttering the code core to its functionality. It does so by adding additional behavior that is the advice to the existing code. For example- Security is a crosscutting concern, in many methods in an application security rules can be applied, therefore repeating the code at every method, defining the functionality in a common class, and controlling were to apply that functionality in the whole application.