Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Safe sex is defined as "Sexual activity engaged in by people who have taken precautions to protect themselves against sexually transmitted diseases such as AIDS." This is also referred to as safer sex, or protected sex, while unsafe sex or unprotected sex is sexual activity engaged in by people who have not taken precautions to protect themselves against sexually transmitted infections. Some sources suggest the use of safer sex is preferable to safe sex, as this reflects that risk is reduced, not avoided.