Movement

The engine of the watch, responsible for keeping time and powering all its functions. Movements include mechanical, automatic, quartz, and hybrid types, each with its own unique attributes.

Crown

A mechanism used to wind the movement and adjust settings such as the date and time. Crowns may screw down to enhance water resistance by forming a seal against moisture.

Pusher

Buttons attached to the watch case that control specific functions, such as operating a chronograph or adjusting the date.

Lugs

Projections on the watch case that allow the attachment of a strap or bracelet, ensuring a secure fit to the wrist.

Rotor

An oscillating weight found in automatic watches that winds the mainspring using the wearer’s wrist motion, powering the watch without manual winding.

Strap

A band, typically made of leather, rubber, or fabric, that secures the watch to the wrist. Metal variants are called bracelets and are often made from stainless steel, titanium, or precious metals.

Subdial

A smaller dial within the main dial used to display additional complications such as chronograph readouts, seconds, or date.

Exhibition Caseback

A transparent case back, often made from sapphire or mineral crystal, allowing visibility of the movement’s intricate workings.

Hour Marker

Indicators on the dial that show the hours, often in the form of numerals, batons, or dots, to assist in time reading.

Case

The protective outer shell that encases the movement, safeguarding it from external elements. Cases can be made from various materials, including stainless steel, gold, titanium, and ceramic.

Crystal

The transparent cover over the dial that protects it from scratches and impacts. Common materials include sapphire crystal, mineral glass, and acrylic.

Bezel

A ring surrounding the crystal, often rotating and used to track elapsed time or for decorative purposes.

Date Window

An aperture on the dial displaying the current date, often magnified by a cyclops lens for better visibility.

Hands

The pointers that move across the dial to indicate the time, including hour, minute, and seconds hands, which can vary in design.

Gasket

Seals made from rubber or synthetic materials that ensure the watch’s water resistance by preventing moisture and dust from entering the case.

Helium Escape Valve

A valve found in professional diving watches that allows helium to escape during decompression, preventing damage to the watch from pressure buildup.

Power Reserve Indicator

A feature that shows the remaining energy in the movement, indicating when the watch needs to be wound.

Tachymeter

A scale, usually on the bezel or dial, used to calculate speed based on time traveled over a fixed distance.

Chronograph

A stopwatch function integrated into the watch, allowing for the measurement of elapsed time. It typically includes subdials for seconds, minutes, and hours.

Deployment Clasp

A type of clasp that unfolds into segments, allowing the strap or bracelet to open wide for easy wear and removal, with a secure closure when fastened.

Crown Guard

Projections on the case designed to protect the crown from accidental knocks or damage.

Anti-Reflective Coating

A treatment applied to the crystal to reduce glare and improve legibility by minimizing reflections.

Chapter Ring

The outermost ring on the dial, often marked with minute or second indices, to aid in precise time reading.

Minute Repeater

A complication that chimes the hours, quarters, and minutes upon request, allowing the wearer to hear the time.

Moon Phase Indicator

A feature that shows the current phase of the moon as viewed from Earth, often found on the dial or as a subdial.

Tourbillon

A complex mechanism that compensates for the effects of gravity on the watch’s timekeeping accuracy, often visible through an exhibition case back.

Annual Calendar

A complication that accounts for months with different lengths and only requires adjustment once a year, at the end of February.

Perpetual Calendar

A sophisticated complication that automatically adjusts for different month lengths and leap years, requiring minimal manual adjustments.