Catalysis is a process that speeds up chemical reactions without being consumed in the reaction itself. Catalysts, the substances that facilitate this process, lower the energy required for a reaction to occur, allowing it to happen more quickly or at lower temperatures. This is important in various industries, including pharmaceuticals and energy production, where efficiency is crucial. There are two main types of catalysis: homogeneous and heterogeneous. In homogeneous catalysis, the catalyst is in the same phase as the reactants, while in heterogeneous catalysis, the catalyst is in a different phase. Both types play vital roles in improving reaction rates and selectivity in chemical processes.