By today’s standards, a vape pen and a mod are vaporizers. Technically they are atomizers that atomize the oils and e-juice essentially vaporizing the oils. This is almost the same thing as vaporizing so for lamen terms they are the same. A true vaporizer uses the proper heat to get the oils to the proper temperature that they beginning to boil off of the plant matter or concentrate and turn to vapor. Atomizers heat the oils and e-juice to a slightly higher temperature so that they make big clouds. If the pen is for just concentrates it is usually heating up so much the fats and lipids also vaporize.