Waterfall plans everything upfront and struggles with changes; Agile works in short sprints with planning and reevaluation built in. Most real projects sit somewhere between these two extremes.
Have you ever heard someone Talk about Agile vs Waterfall project management? And you're like, what? What does that mean? Waterfall refers to when you have a project and you sit down and plan it all in advance. I'm going to sequentially plan every step and the only way we're going to go is forward. If things come up. If issues arise, you got to scrap your whole plan and go figure out a new river to go down. Same with your projects. If your project is pre planned but new things pop up, you've got to replan that entire project in waterfall because it's all about planning all of our steps in advance and going only forward. Agile is all about iteration. So you plan a little, you do a little and then you look around. Each cycle of planning and doing and re evaluating is called a sprint. And you do many short sprints over the journey of a project. You're just taking it one chunk at a time and planning in very small intervals and evaluating yourself on the sub result you get at the end of each sprint. Agile and waterfall are extreme sides of the project management spectrum and most people fall somewhere in the middle.
