Hair dryers, either straight, ceramic, or hair curling irons, are appliances used in the home, a beauty salon or in the office to dry hair quickly and efficiently. Hair dryers, especially newer ones, which are available with multiple heat settings, may be used for body and face hair and for other purposes. Hair dryers have many advantages over conventional hairbrushes or combs; dryers can be used for a variety of hair types including fine or thick, for multiple styles at one time, and they provide more even heat distribution than traditional tools.

A hair dryer, also called a hairdryer, hair dryer or rotary hair dryer is an electrically powered device that gently blows warm or dry air over wet hair to dry it. Blow dryers allow more control over the delicate shape and design of individual strands, by rapidly controlling and accelerating the formation of temporary molecular bonds in each strand. These bonding molecules are what give hair its permanent shape, including curls and waves. In order to achieve the desired curl, the stylist must apply gentle pressure on the root of the curl, while the hair is still wet, and leave it to dry.

Ceramic and titanium hair dryer models are the most popular, as they have a smooth surface and advanced technology that generates minimal heat. The ceramic hair dryer models are extremely quiet while generating high temperatures; they are also the most durable. The greatest difference between the ceramic and titanium is the ceramic models are made of a hard material while titanium is made entirely out of a soft metal. One of the main differences between ceramic and titanium is that titanium is not as popular as ceramic hair dryers because it is less expensive, which means that hair stylists may opt to purchase a ceramic model instead of a titanium model.

A blow dryer with a fan, called a portable hair dryer, allows users to control the speed of the airflow, allowing the user to adjust the temperature according to their desired style. The most common style for a blow dryer consists of running the hair dryer from the opposite end of the head, blowing across the crown of the head and away from the roots. The other end of the blow dryer must be used to blow air through the hair. This is known as "running the hair dryer", which can be accomplished by turning the motor on the side of the unit, or even running the blow dryer without the fan. Portable hair dryer fans use a vent that allows the hot air produced from the hair dryer to ventilate the air surrounding the hair dryer.

Hair stylists and models will often measure the wattage of the dryer in order to determine if the model is suitable for their customers. A low wattage hair dryer will produce much less heat than a high wattage model, so it will require less time to get the hair dryer ready and dried. This is also an important factor when choosing a style. If the blow drier runs out of steam during the drying process, the style will not look as good as if it is drying quickly. Some styles require extremely high wattage models in order to achieve their best results.

It may be difficult for stylists who do not regularly use high wattage blow dryers to judge the appropriate wattage for their clients. Some blow dryers have settings that can control the speed and strength of the airflow. High wattage models will produce more heat, so it is important to consider what is available in the styling product. The best way to decide what is best for you is to try the product out yourself, after using it for a while. Once you find the right style, you can return to a high wattage blow dryer if you are not happy with your choice.