The ΛCDM model (Lambda Cold Dark Matter) represents our current best understanding of the Universe's composition, structure, and evolution from the Big Bang to today. This sophisticated framework reveals that ordinary matter—everything we can see and touch—comprises merely 5% of the Universe. The remaining 95% consists of mysterious dark matter (27%) and dark energy (68%), represented by the cosmological constant Lambda (Λ).</p><p>Developed through decades of observations beginning in the 1980s, ΛCDM successfully explains three crucial cosmic phenomena. First, it accounts for the Universe's accelerating expansion, discovered in 1998 through distant supernovae observations. Second, it precisely predicts the cosmic microwave background radiation patterns observed by satellites like Planck, showing temperature fluctuations of just 0.00001 degrees. Third, it explains how galaxies and galaxy clusters formed from tiny density variations in the early Universe.</p><p>The model's "cold" dark matter component moves slowly compared to light speed, allowing gravity to sculpt the cosmic web's magnificent large-scale structure over 13.8 billion years. Computer simulations based on ΛCDM create virtual universes that remarkably match our observations of galaxy distributions across billions of light-years. While mysteries remain about dark matter's true nature, ΛCDM provides the essential framework for modern cosmology, guiding everything from galaxy formation studies to predictions about our Universe's ultimate fate.