According to Wikipedia…
Estheticians are licensed professionals who are experts in maintaining and improving healthy skin.
An esthetician’s general scope of practice is limited to the epidermis (the outer layer of skin).
Estheticians work in many different environments such as salons, med spas, day spas, skin care clinics, and private practice. Estheticians may also specialize in machine treatments such as microdermabrasion, microcurrent (also called non-surgical “face lifts”), cosmetic electrotherapy treatments (galvanic current, high frequency), LED (light emitting diode), ultrasound/ultrasonic (low level), and mechanical massage (vacuum and g8 vibratory).
The esthetician may undergo special training for treatments such as laser hair removal, permanent makeup, and electrology.
In the US, estheticians must be licensed in the state in which they are working and are governed by the cosmetology board of that state. Estheticians must complete a minimum 450–1500 hours of training and pass both a written and hands-on exam in order to be licensed by the state.
Additional post graduate training is sometimes required when specializing in areas such as medical esthetics (working in a doctor’s office). Estheticians work under a dermatologist’s supervision only when employed by the dermatologist’s practice.
Estheticians treat a wide variety of skin issues that are cosmetic in nature, such as mild acne, hyperpigmentation, and aging skin. Skin disease and disorders are referred to a dermatologist or other medical professional. The word esthetician is an alternative spelling of aesthetician, a derivation of the word aesthetic, or beauty.