The Casimir effect is a quantum phenomenon arising from the zero-point energy of the electromagnetic field, leading to an attractive or repulsive force between objects due to boundary conditions. This effect has been extensively studied both experimentally and theoretically, with recent developments focusing on its applications in various fields of physics. The Casimir force depends strongly on the geometry, topology, and size of the boundaries, making it a unique manifestation of quantum vacuum effects. Theoretical advancements include the use of zeta-functional regularization and heat kernel expansion to handle divergences in field theory, allowing for precise calculations of vacuum energy and Casimir forces in different configurations. These methods have been applied to a wide range of geometries, including parallel plates, spheres, cylinders, and more complex topologies. The effect is also influenced by real-world factors such as finite conductivity, nonzero temperature, and surface roughness, which are crucial for understanding the Casimir force in practical scenarios. Experimental studies have confirmed the Casimir effect through high-precision measurements, with recent results providing stringent constraints on hypothetical long-range interactions and deviations from Newtonian gravity. The review highlights the importance of the Casimir effect in condensed matter physics, quantum field theory, and cosmology, emphasizing its role in understanding vacuum polarization, particle creation, and the behavior of quantum fields in non-trivial backgrounds. Theoretical and experimental progress continues to refine our understanding of this fundamental quantum phenomenon, with ongoing research exploring its implications for nanotechnology, quantum electrodynamics, and the nature of vacuum energy.The Casimir effect is a quantum phenomenon arising from the zero-point energy of the electromagnetic field, leading to an attractive or repulsive force between objects due to boundary conditions. This effect has been extensively studied both experimentally and theoretically, with recent developments focusing on its applications in various fields of physics. The Casimir force depends strongly on the geometry, topology, and size of the boundaries, making it a unique manifestation of quantum vacuum effects. Theoretical advancements include the use of zeta-functional regularization and heat kernel expansion to handle divergences in field theory, allowing for precise calculations of vacuum energy and Casimir forces in different configurations. These methods have been applied to a wide range of geometries, including parallel plates, spheres, cylinders, and more complex topologies. The effect is also influenced by real-world factors such as finite conductivity, nonzero temperature, and surface roughness, which are crucial for understanding the Casimir force in practical scenarios. Experimental studies have confirmed the Casimir effect through high-precision measurements, with recent results providing stringent constraints on hypothetical long-range interactions and deviations from Newtonian gravity. The review highlights the importance of the Casimir effect in condensed matter physics, quantum field theory, and cosmology, emphasizing its role in understanding vacuum polarization, particle creation, and the behavior of quantum fields in non-trivial backgrounds. Theoretical and experimental progress continues to refine our understanding of this fundamental quantum phenomenon, with ongoing research exploring its implications for nanotechnology, quantum electrodynamics, and the nature of vacuum energy.