Magnetoencephalography (MEG) is a non-invasive imaging technique used to measure the magnetic fields produced by electrical activity in the brain. It helps researchers and clinicians understand brain function by providing real-time data on neural activity, making it valuable for studying conditions like epilepsy and brain tumors. MEG works by using sensitive devices called superconducting quantum interference devices (SQUIDs) to detect these magnetic fields. The information gathered can be used to create detailed maps of brain activity, aiding in both research and clinical applications, such as planning surgeries or assessing cognitive functions.