Ultrasound machines are medical devices that use high-frequency sound waves to create images of the inside of the body. These machines are commonly used in prenatal care to monitor the development of a fetus, but they can also help visualize organs, tissues, and blood flow in various medical conditions. The process involves placing a gel on the skin and using a handheld device called a transducer to send and receive sound waves. The echoes produced are converted into images displayed on a monitor, allowing healthcare professionals to assess and diagnose various health issues without invasive procedures.