A professional learning network (PLN) is a deliberately formed network of people and resources that can guide one's learning goals and professional development needs. The key aspects of a PLN are connecting, contributing, and collaborating. The document discusses how Twitter can be used to build a PLN, noting that the author gained 22 followers and followed 465 people over a semester to grow their network. They provide honorable mentions of three Twitter accounts - @TechEd_UofA, @kathyschrock, and @web20classroom - that support their PLN through sharing information, collaboration opportunities, and motivation. The closing remarks emphasize that a PLN is never complete and one should continue connecting, contributing, and collaborating
