Which of the following is a common electrical tool used in cosmetology?

In the realm of cosmetology, electrical tools are essential for various hair and beauty treatments. The hair dryer and curling iron are quintessential electrical tools commonly found in salons. They utilize electrical energy to function, allowing hairstylists to dry hair quickly and create curls or waves, which are integral to many hairstyles.

While manicure scissors and nail files are important tools for nail care, they do not rely on electricity and therefore are not classified as electrical tools. Similarly, a facial steamer, while it is an electrical device, is not as universally recognized or used as the hair dryer or curling iron in cosmetology, especially compared to their prevalence in daily hairstyling practices. Thus, the hair dryer or curling iron stands out as the correct answer due to its widespread application and significance in the field.