E juice, vape juice, e liquid all refer to the same thing. These are just different names for the same thing. E-cigarette or a vape is a device in which e juice is converted into the vapors form. There are different types of e juices. Different e cigarettes or vapes use different types of e juices. Some are high in nicotine and some are low in nicotine. Some are even nicotine free e juices.