Ultrasound is a non-invasive diagnostic imaging technique that uses high-frequency sound waves to create images of the inside of the body. It is commonly used in obstetrics to monitor the development of a fetus during pregnancy, but it also plays a vital role in examining organs such as the liver, kidneys, heart, and blood vessels. The procedure is considered safe because it does not use ionizing radiation like X-rays or CT scans. During an ultrasound exam, a transducer emits sound waves that bounce off internal structures, and a computer converts these echoes into real-time images on a screen.