In this seminar we review the highlights of the study of Titan's interaction with its plasma environment from Cassini magnetometer (MAG) and plasma instruments during the first 4 years of the mission. These observations have confirmed that a well defined induced magnetosphere (similar to that found at Mars, Venus and comets) forms around the moon as a result of the pile up and draping of the external magnetic field as the external plasma is massloaded with the moon's cold atmospheric ions. However, unlike other non magnetized atmospheric bodies, Cassini observations in the vicinity of Titan's orbit reveal that its plasma environment is extremely variable. This variability can be used to measure important properties such as Titan's induced magnetosphere replenishment time, as occurred during Cassini's 32nd flyby, when the moon was observed outside Saturn's magnetosphere for the first time.