VSEPR Theory, or Valence Shell Electron Pair Repulsion Theory, is a model used in chemistry to predict the shape of molecules. It is based on the idea that electron pairs around a central atom will arrange themselves as far apart as possible to minimize repulsion. This helps determine the three-dimensional structure of molecules, which is crucial for understanding their reactivity and properties. The shapes predicted by VSEPR Theory include common geometries like linear, trigonal planar, and tetrahedral. By knowing the arrangement of atoms and electron pairs, chemists can better understand how molecules interact with each other, which is essential in fields like biochemistry and pharmaceuticals.