There are few humidifier types. The most basic type is the wick humidifier that functions based on the moisture in the room itself. Other types are vaporizers, impellers or ultrasonic humidifiers. I would suggest you to read more information about humidifier if you are looking for the best humidifier to buy for your home or office. After all, you buy a new humidifier for your better health, you better know what you are getting out of the humidifier you intend to buy:) Sometime, it also nice to know that there few different types of humidifier, and each of them has their functions, so buy the one that you think it is best for you.