Electroencephalography, or EEG, is a medical test that measures electrical activity in the brain. It involves placing small electrodes on the scalp, which detect brain waves and record them as wavy lines on a computer screen. This non-invasive procedure helps doctors understand brain function and diagnose conditions like epilepsy, sleep disorders, and brain injuries. During an EEG test, patients are usually asked to relax or sleep while the electrodes capture brain activity. The results can reveal important information about how the brain works and help guide treatment options. Overall, EEG is a valuable tool in neuroscience and clinical practice.