A "paradigm shift" refers to a fundamental change in the underlying assumptions or practices within a particular field or discipline. This concept, popularized by Thomas Kuhn in his book "The Structure of Scientific Revolutions," illustrates how scientific progress often occurs not through gradual accumulation of knowledge, but through revolutionary changes that redefine the framework of understanding. Such shifts can occur in various areas, including science, technology, and social norms. For example, the transition from Newtonian physics to Einstein's theory of relativity represents a paradigm shift in our understanding of space and time. These shifts can lead to new ways of thinking and can significantly impact society and culture.