Separation of concerns is one of the oldest concepts in computer science. The term was coined by Dijkstra in 1974. It is important because it simplifies software, making it easier to develop and maintain. Separation of concerns is commonly achieved by decomposing an application into components. There are, however, crosscutting concerns, which span (or cut across) multiple components. These kinds of concerns cannot be handled by traditional forms of modularization and can make the application more complex and difficult to maintain.