Electroencephalography or ECG is a technique that helps monitor and interpret the activity of brain impulses. The technique is highly safe and makes use of small, flat metal disks or electrodes, which are fixed to the scalp of the patient using a sticky substance. The electrodes are connected with a computer that records the electric signals of the brain, and, thus, helps the doctor or ECG specialist to interpret the brain activity by doing a comparison of the recording with normal brain wave patterns. Our brain is nothing but a complex of neuronal circuits that transmit electric signals. Because ECG can record this brain activity, it is of significant use in medical fields for diagnosis of brain disorders like epilepsy, seizures, brain tumours, Alzheimer’s disease, etc. ECG is also recommended after severe brain damage or a brain surgery, and also in cases where the cause of any abnormality in the body might be linked to brain functioning like sleeping disorders and sudden loss of consciousness. ECG cannot calculate intelligence.