An electrocardiogram (ECG or EKG) is a medical test that records the electrical activity of the heart over a period of time. It uses small electrodes placed on the skin to detect electrical signals produced by heartbeats. The resulting graph shows the timing and strength of these signals, helping doctors assess heart health. ECGs are commonly used to diagnose various heart conditions, such as arrhythmias, heart attacks, and heart disease. The test is non-invasive, quick, and painless, making it a valuable tool in routine check-ups and emergency situations to monitor heart function.