Electroencephalography (EEG) is a diagnostic test that records and measures the electrical activity produced by nerve cells in the brain. This test helps identify the presence and location of functional disorders by monitoring the brain's complex electrical waves. During an EEG application, electrodes made of silver or gold alloy are placed on the scalp with the aid of a gel. This method plays a crucial role in the diagnosis and evaluation of various neurological diseases and provides valuable insights into the effectiveness of communication between brain regions.