The phrase "major challenge" refers to a significant problem or difficulty that presents a substantial obstacle in achieving something. It is an issue that requires considerable effort, resources and creativity to overcome, and it may require innovative solutions and strategies to address effectively. The term can be used to describe any situation where the complexity of the task at hand poses a significant threat or risk to success, whether it's in personal life, business, politics, science, technology, etc. It implies that the challenge is not only difficult but also important enough to demand attention and action from those who are affected by it.