Aspects are a natural evolution of the object-oriented paradigm. They provide a solution to some difficulties you may have encountered with modularizing your object-oriented code: sometimes functionality just doesn't fit! You've probably found yourself repeating the same lines of code in lots of different object-oriented classes because those classes each need that functionality, and so you can't easily wrap it up in a single place. Good examples of this kind of code are audit trails, transaction handling, concurrency management, and so on. You can now modularize such code with aspects. Aspect-Oriented Software Development (AOSD). Provides unique and advanced program structuring and modularization techniques. The implementation of software applications using AOSD techniques results in a better implementation structure which has an impact on many important software qualities such as enhanced reusability and reduced complexity. In turn, these software qualities lead to an improved software development lifecycle and, hence, to better software.