- Bacteria
- One-celled microorganisms that reproduce by dividing in two (binary fission); responsible for many common infections in a shop setting.
- Binary fission
- The process by which a bacterium reproduces by simply dividing into two cells.
- Staphylococci
- Round, pus-producing bacteria that grow in clusters and can cause skin abscesses and infections.
- Virus
- A submicroscopic infectious agent that must invade a living host cell to reproduce; smaller than bacteria.
- Fungi
- Microorganisms (molds, mildews, yeasts) that can cause infections such as ringworm; tinea is a fungal infection.
- Direct transmission
- Spread of disease from person to person through contact, such as a client coughing onto the barber's hands.
- Indirect transmission
- Spread of disease through a contaminated object, such as an unsanitized comb passing a pathogen to the next client.
- Cross-contamination
- The spread of contaminants from one surface, tool, or person to another; prevented by using disinfected implements per client.
- Sanitation (cleaning)
- The lowest level of decontamination — soap, water, and scrubbing remove visible debris but do not kill pathogens.
- Disinfection
- Using an EPA-registered chemical to kill most pathogens on hard, nonporous tools; the barbershop standard between clients.
- Sterilization
- The highest level of decontamination — destroys all microbial life, including spores; requires an autoclave.
- Autoclave
- A device that uses pressurized steam to truly sterilize metal implements, destroying all microorganisms including spores.
- Clean before you disinfect
- The required order: remove all visible debris and oils first, because they shield germs from the disinfectant.
- EPA-registered disinfectant
- A disinfectant approved for use on hard, nonporous surfaces; barber tools need one labeled bactericidal, virucidal, and fungicidal.
- Contact (dwell) time
- The time a disinfectant must stay wet on a surface to kill pathogens, as stated on its label; wiping too quickly fails to disinfect.
- Bloodborne pathogens
- Infectious microorganisms in blood (hepatitis B, hepatitis C, HIV); tools that contact blood must be sterilized or discarded.
- Hand hygiene
- Handwashing/sanitizing — one of the most effective barriers against transmission of infection between clients.
- Chemical burn
- Skin damage (redness, stinging) from overexposure to a strong product such as an alkaline lightener or relaxer.
- Allergic contact dermatitis
- A lasting skin sensitivity reaction that can develop from repeated chemical overexposure without protection.
- Ventilation (chemical safety)
- Good airflow reduces inhalation of hazardous fumes from relaxers, lighteners, and smoothing products.
- Formaldehyde (smoothing products)
- A recognized hazard that some hair-smoothing/keratin products can release when heated; a reason for ventilation and caution.
- Cranium
- The part of the skull that encloses and protects the brain; made of eight bones.
- Parietal bones
- The paired bones that form the crown and upper sides of the cranium.
- Maxillae
- The two upper bones that join to form the upper jaw and hold the upper teeth.
- Zygomatic (malar) bones
- The paired bones that form the prominence of the cheeks.
- Temporomandibular joint (TMJ)
- The joint that allows the lower jaw to open and close; considered when positioning a client for a shave.
- Temporalis
- The muscle covering the side of the skull above and in front of the ear that helps close the jaw during chewing.
- Sternocleidomastoid
- The muscle running from the collarbone to behind the ear that turns and tilts the head.
- Buccinator
- The cheek muscle that compresses the cheeks (used in blowing and chewing); the 'trumpeter's muscle.'
- Trapezius
- The muscle covering the back of the neck and upper shoulders; relevant when massaging the upper back.
- Origin (muscle)
- The fixed, non-moving attachment of a muscle (the insertion is the movable end).
- Massage direction (insertion to origin)
- Manipulations are generally directed from a muscle's insertion toward its origin; the wrong direction can strain tissue.
- Integumentary system
- The skin and its appendages (hair, nails, sweat and oil glands) — the body's largest organ and first line of defense.
- Epidermis
- The outermost layer of the skin — the layer a clipper, comb, and razor contact; melanin is made in its deepest part.
- Dermis
- The deep, living skin layer containing blood vessels, nerve endings, hair follicles, and sweat and oil glands.
- Subcutaneous (adipose) layer
- The fatty layer beneath the dermis that stores fat and provides insulation and a protective cushion.
- Melanin
- The pigment, produced in the deepest part of the epidermis (basal layer), that gives skin and hair their color.
- Sudoriferous gland
- A sweat gland that secretes sweat to help regulate body temperature.
- Sebaceous gland
- An oil gland of the skin that secretes sebum to lubricate the skin and hair.
- Endocrine system
- The body system of ductless glands that produces hormones regulating growth, including hair growth.
- Nervous system
- The body system that, with the nerves, coordinates the senses such as touch and temperature felt during a service.
- Androgenic alopecia
- Hereditary, hormone-related hair loss (male pattern baldness) showing as a receding hairline and thinning crown; noncontagious.
- Traction alopecia
- Hair loss along the hairline caused by constant tension, such as very tight braids; noncontagious.
- Telogen effluvium
- Temporary shedding a few months after a major stressor (surgery, high fever) on an otherwise healthy scalp.
- Alopecia totalis
- Complete loss of hair over the entire scalp.
- Tinea capitis
- Scalp ringworm — a contagious fungal infection; the barber must refuse the service and refer to a physician.
- Seborrheic dermatitis
- A chronic inflammatory scalp condition with greasy yellowish scales and redness; noncontagious and serviceable.
- Dandruff (pityriasis capitis simplex)
- Common, noncontagious dry flaking of the scalp, managed with medicated anti-dandruff shampoo.
- Contagious vs. serviceable
- Decision rule — refuse and refer for contagious conditions (ringworm) or broken/infected skin; service noncontagious conditions.
- Hepatitis B / C and HIV
- Bloodborne diseases a barber can be exposed to through a nick or cut; the reason blood-contact tools are sterilized or discarded.
- Cutting shears
- Standard shears with two solid blades used to remove length and shape the cut.
- Thinning (texturizing) shears
- Shears with notched, toothed blades that remove bulk and blend without changing the overall length.
- Trimmer / outliner (edger)
- A tool used to detail and edge the hairline, sideburns, and neckline with crisp, clean lines.
- Detachable blade (clipper)
- A snap-on clipper blade that lets the barber quickly swap cutting sizes by changing the whole blade.
- Adjustable blade (clipper)
- A single clipper blade with a lever that varies the cutting size without changing the blade.
- Clipper guard
- An attachment comb that sets the length the clipper leaves; higher guards leave longer hair (used to build a fade).
- Clipper oil
- Lubricant applied to clipper blades so they glide, cut cleanly, run cooler, and resist rust.
- Straight razor
- A barbering razor with a fixed blade kept sharp with a hone and strop; used for shaving and sharp outlines.
- Changeable-blade (guarded) razor
- A razor that takes a fresh disposable blade per client, reducing the need for honing and stropping.
- Hone
- An abrasive sharpening stone used to grind and sharpen a dull or rough straight-razor edge.
- Strop
- A leather or fabric strip used to smooth and align an already-sharp razor edge just before shaving; it does not grind.
- Neck duster (neck brush)
- A brush used to remove loose, cut hair clippings from the client's face and neck at the end of a service.
- Neck strip
- A disposable strip placed around the neck before the cape to keep the cape off bare skin and prevent cross-contamination.
- Hot towel cabinet (towel steamer)
- Equipment that keeps towels warm and moist to soften the beard and open the pores before a shave.
- Sharp-implement storage
- Store razors and shears clean, disinfected, dry, and with edges shielded in a closed container or drawer.
- Comb (barbering)
- A tool to part, distribute, and control hair during cutting; the foundation of shear-over-comb and clipper-over-comb work.
- Client consultation
- The initial step of discussing the desired style, lifestyle, and hair history before any service.
- Hair analysis
- Assessing the hair's elasticity, porosity, density, texture, and growth patterns before a service.
- Elasticity
- How far a wet strand stretches and returns without breaking — a measure of the hair's strength.
- Porosity
- The hair's ability to absorb moisture or liquids, judged by the cuticle; high-porosity hair absorbs chemicals faster.
- Cowlick (whorl)
- A strong swirl of hair growth, often at the crown, that affects how the hair falls and must be cut for.
- Shampooing (purpose)
- Cleansing the hair and scalp of dirt, oil, and product buildup; usually done before most barbering services.
- Warm (lukewarm) water
- The recommended water temperature for comfortably and effectively shampooing a client.
- Conditioner (acidic pH)
- A slightly acidic product that closes and smooths the cuticle after shampooing, adding shine and manageability.
- Clarifying shampoo
- A shampoo used periodically to remove heavy residue from styling products, hard-water minerals, and oils.
- Medicated (anti-dandruff) shampoo
- A shampoo formulated to control flaking and itching from a dry, scaly scalp condition.
- Deep (penetrating) conditioner
- A conditioner left on for several minutes, sometimes with heat, to penetrate the cortex and restore strength to damaged hair.
- Detangling wet hair
- Comb from the ends upward toward the scalp to minimize breakage.
- Elevation
- The angle at which hair is lifted away from the head before cutting; the main control over a cut's shape and weight.
- Zero elevation
- Holding hair flat with no lift and cutting straight across, producing a blunt, one-length (solid) form.
- Guideline (guide)
- The first cut length to which following sections are matched; a traveling guide keeps lengths consistent.
- Graduation
- A cut in which lengths stack at a low elevation to build a graduated, weighted shape with a visible weight line.
- Weight line
- The line where the weight of the hair concentrates and the cut appears heaviest.
- Layering
- Cutting hair lifted to 90° or higher to remove weight; lifting all hair to one point gives increasing (uniform) layers.
- Shear-over-comb
- Cutting hair over the teeth of a comb to blend and taper short hair, especially on the sides, back, and nape.
- Fade
- A taper that blends from very short at the bottom to longer above using progressively higher clipper guards, with no visible line.
- Texturizing (thinning)
- Removing bulk from a section without changing its overall length so the style sits closer to the head.
- Slithering (effilating)
- Sliding the shears down a strand to remove weight gradually.
- Permanent wave (cold wave)
- A chemical service that uses thioglycolate to break and re-form the hair's disulfide bonds, adding a lasting curl.
- Disulfide bonds
- Strong sulfur cross-links that hold the hair's shape; broken and re-formed during a perm or relaxer.
- Neutralizer (perm)
- The oxidizing solution applied after the waving lotion to rebuild the disulfide bonds so the new curl holds.
- Perm rod size
- The factor that determines the size of the curl — smaller rods make tighter curls, larger rods looser waves.
- Chemical hair relaxer
- A service that straightens overly curly hair by breaking and rearranging its bonds into a straighter form.
- Sodium hydroxide relaxer
- A strong, high-pH (lye) relaxer that straightens hair quickly and requires a protective base cream on the scalp.
- Thioglycolate (thio) relaxer
- A milder relaxer that works at a lower pH than a hydroxide relaxer; incompatible with hydroxide on the same hair.
- Relaxer incompatibility
- Thio and hydroxide relaxers must never be used on the same hair — the differing chemistries can break it.
- Base cream (relaxer)
- A protective cream applied to the scalp before a sodium hydroxide relaxer to shield the skin from the corrosive alkali.
- Neutralizing shampoo (relaxer)
- An acid-balancing shampoo used after a hydroxide relaxer to stop the relaxing action and rebalance the pH.
- Strand test
- A preliminary test on a small section to check how the hair will respond to a relaxer or color before the whole head.
- Overlapping (chemicals)
- Applying fresh relaxer or color onto previously processed hair; causes over-processing, breakage, or banding — avoid it.
- Temporary color
- Color that coats the surface of the hair and washes out after one or several shampoos because it does not penetrate the cortex.
- Developer (hydrogen peroxide)
- The oxidizing agent mixed with permanent color or lightener to develop color and lift natural pigment.
- Lightener (bleach)
- A product that lightens hair by oxidizing and diffusing the natural melanin in the cortex.
- Patch (predisposition) test
- A small application of oxidation color behind the ear or inside the elbow 24–48 hours ahead to check for allergy.
- Depositing color
- Adding pigment to make the hair a darker or richer shade (as opposed to removing pigment).
- Level (haircolor)
- The lightness or darkness of a color, on a numbered scale; separate from tone.
- Tone (haircolor)
- The warmth or coolness of a color; an unwanted tone is corrected with the opposite color (blue cancels orange).
- Single-process color (virgin application)
- Applied about a half inch off the scalp first, then the scalp area last, because body heat processes the base faster.
- Heat-protectant product
- A product applied before a high-heat flat iron to shield the hair from dryness and breakage.
- Thermal styling iron
- A curling or flat iron that uses heat to temporarily shape, curl, or straighten the hair.
- Blow-drying direction
- Aim airflow from the scalp toward the ends, following the cuticle, for a smooth finish.
- Hairspray (finishing spray)
- A finishing product used to hold a completed style in place.
- Smoothing serum
- A lightweight finishing product that adds shine and tames frizz and flyaways without strong hold.
- Waterproof shampoo cape
- A cape worn over a neck strip or towel before a shampoo to keep water and product off the client's clothing.
- Cortex
- The middle layer of the hair shaft where color and chemical changes (perms, relaxers, lightening) take place.
- Cuticle
- The outer protective layer of the hair shaft; lies flat for shine and lifts to let chemicals penetrate.
- Hot towel (shave)
- A warm, moist towel applied before a shave to soften the beard hair and open the pores.
- Lather (shave)
- Shaving cream or soap applied to soften the hair and lubricate the skin so the razor glides safely.
- With the grain
- Stroking the razor in the direction the hair grows — the standard first-pass direction for a comfortable shave.
- Skin stretching (shave)
- Pulling the skin taut with the free hand to create a smooth, flat surface so the razor cuts evenly and avoids nicks.
- Freehand stroke
- A gliding cutting movement drawn toward the barber — the most common stroke in a facial shave.
- Fourteen shaving areas
- The traditional set of facial regions a classic professional shave is divided into for thorough coverage.
- Astringent / aftershave
- Applied after a shave (with a cool towel) to soothe the skin and help close the pores.
- Shave contraindication
- Do not shave over an open cut, sore, or active skin infection in the shave area — refuse or work around it.
- Mustache design
- Proportion is chosen primarily to relate to the size and shape of the client's facial features.
- Beard outlining
- Establishing clean cheek and neckline borders to give the beard a defined, balanced shape that frames the face.
- Effleurage
- A light, gentle, continuous stroking massage movement used to begin and end a facial massage.
- Petrissage
- A kneading massage movement in which the skin and tissue are gently lifted, squeezed, and rolled.
- Steam / warm towels (facial)
- Applied before extractions or product to soften the skin and open the pores so they can be cleansed.
- Client intake form
- Reviewed before a facial for product allergies and skin conditions to avoid triggering or worsening a reaction.
- Pore (open vs. close)
- Heat (towel/steam) opens pores before cleansing or shaving; a cool towel or astringent helps close them afterward.
- Second-pass shave
- A closer follow-up pass taken carefully after re-lathering, never on dry skin.
- Beard softening
- The goal of the hot towel and lather before a shave — softening hair and opening pores for a closer, smoother cut.
- Facial massage purpose
- Relaxes the client, stimulates circulation, and aids product application during a facial treatment.