The ultrasound equipment uses high frequency sound waves to create images of the organs and structures inside the body. A computer processes the waves to create an image. Through ultrasound doctors are able to see the heart, blood vessels, kidneys, liver, prostate, gall bladder, ovaries, etc. and during pregnancy, it is able to see the fetus inside the uterus.
You will not feel any discomfort since the procedure is not invasive and it does not hurt. You will be laying down and gel will be applied to the area that will be visualized.