Shielding is a protective measure used to block or reduce the impact of harmful radiation or electromagnetic fields. It involves using materials, such as lead or concrete, to absorb or deflect radiation, ensuring safety in environments like hospitals, nuclear power plants, and research facilities. In the context of electronics, shielding refers to enclosing sensitive components in conductive materials to prevent interference from external electromagnetic signals. This is crucial for maintaining the performance of devices like computers, smartphones, and communication systems, where unwanted signals can disrupt functionality.