The Friedmann-Lemaître-Robertson-Walker Metric (FLRW metric) is a solution to Einstein's equations of general relativity that describes a homogeneous and isotropic universe. It provides a mathematical framework for understanding the large-scale structure of the universe, assuming it is expanding or contracting over time. The FLRW metric incorporates the effects of cosmic expansion, allowing cosmologists to model the universe's evolution. It is fundamental in the study of cosmology, particularly in understanding the Big Bang theory and the overall dynamics of the universe, including its shape and fate.