Intrauterine devices (IUDs) are long-term, reversible forms of birth control that are inserted into a woman's uterus to prevent pregnancy. Other terms commonly used for IUDs are "intrauterine contraceptives" or "intrauterine systems". The two main types of IUDs are hormonal and copper, which work in different ways to prevent pregnancy. Some other terms used to refer to IUDs specifically include "hormonal IUD" and "copper IUD". IUDs are a highly effective form of birth control and are becoming more popular due to their convenience and long-lasting effects. Regardless of the terminology used, IUDs provide many women with a safe and reliable option for preventing unplanned pregnancies.