The document discusses project-based learning (PBL), an approach where students work in teams to explore real-world problems. It provides an example where a high school team had to make a local bank more environmentally sustainable on a budget. The students used software like SketchUp and Skype, and consulted experts to complete their project. By using technology like modeling software to make their thinking visible, the students gained 21st century skills through an authentic challenge rather than focusing on the tools themselves.