This video compares the traditional Waterfall model with the modern agile methods of software developments. The video is pretty self-explanatory and gives the viewer a great insight into the topic.
Agile is based on empirical, rather than defined methods of the Waterfall model, is all about light maneuverability and sufficiency for facilitating future development. By defined methods what one means is that one plans first and then enforces these plans. However, Agile methods involve planning what one wants and then adapting these plans to the results.
Once a stage is completed in Waterfall methods there is no going back. In conclusion, Waterfall’s defined stages allow for thorough planning, especially for logical design, implementation and deployment.