Final answer:
In pregnancy, positive signs indicate the presence of a pregnancy with a high degree of certainty and are considered absolute confirmation of pregnancy.
Step-by-step explanation:
In pregnancy, there are three types of signs that can be used to verify pregnancy: positive (definite) signs, presumptive signs, and probable signs. Positive signs indicate the presence of a pregnancy with a high degree of certainty, as they can only be attributed to the fetus. Examples of positive signs include ultrasound visualization of the fetus, fetal movements felt by the mother, and hearing the fetal heartbeat. These signs are considered absolute confirmation of pregnancy.