Analog-Digital Display (ana-digi): Watch that shows the time by means of hour and minute hands (analog display) as well as by numbers (digital display).

Arabic Numerals: Popular counterpart to Roman numerals consisting of 1,2,3, etc; Became popular during the 18th century and typically allow for more space on the dial for complications.

ATM: Commonly used measurement in water resistance; Stands for "atmospheres" or the amount of pressure a watch can withstand before leaking; One atmosphere is equal to 10 meters of water pressure.

Automatic Movement: Type of movement where the mainspring is wound via the movement of one’s own arm; Movement of the arm causes the rotor to rotate, which in turn winds the mainspring; Similar to mechanical movements, except winding is not manual.

Bezel: Retaining ring surrounding the case and securing the crystal; Sometimes incorporates unidirectional or ratcheting movements, as well as additional benefits such as chapter markers.

Case: Timepiece’s container; Protects the movement from dust, dampness and injury; Common case shapes are round, tonneau, rectangular and square.

Chronograph: Timepiece capable of both timekeeping and stopwatch functions; Chronographs are a unique and valued complication due to their ability to measure increments of time.

Chronometer: High-precision timepiece that has been tested and is certified to meet precision standards; Chronometer watches often come with certificates indicating their certified status.

Complication: Any feature added to the timepiece that does not indicate hours, minutes or seconds. Popular complications include chronographs, tachymeters, date windows and exhibition backs.

Crown: Small, cap-like device located on the side of a case that allows the user to set time or manually wind watch.

Crystal: Transparent cover on a watch face that gives view of the dial; Sapphire and mineral are the most common crystals used today.

Date Window: Reveals the numeric day of a given month.

Deployant: Type of clasp that keeps the closing mechanism hidden, creating an uninterrupted look for your bracelet or strap.

Dial: Plate beneath the crystal showcasing the timepiece’s features; Sometimes referred to as the face of a timepiece, the dial indicates hours, minutes and seconds, as well as complications such as date windows and sub-dials.

Dual Deployant: Similar to a deployant clasp, except it uses two hinges to fasten or open, as opposed to one.

Dual Time Zone: Timepiece that simultaneously gives time in two time zones.

Exhibition case: Unique complication wherein a crystal is implemented into the case back, allowing view of the timepiece's movement.

Greenwich Mean Time: Refers to the Royal Observatory in Greenwich, England where mean time is kept; Located at the prime meridian of the world, GMT is thought of as "the world's time".

Jewels: International term referring to the rubies, sapphires or other gemstones used as bearings in a watch movement; These bearings are set to reduce friction in a movement and help the delicate parts of the movement work smoothly and with great precision.

Mechanical Movement: Type of movement where the winding crown is used to power the movement; Needs to be manually wound after an elapsed period of time; Sometimes accompanied by a exhibition back to display its old-fashioned sensibilities.

Mineral Crystal: Technical term for glass; Standard crystal used in timepieces today.

Minute Repeater: Timepiece that sounds hours, quarters and minutes as requested.

Moon Phase: Complication on a timepiece that displays the various stages of the moon; Stages include new moon, first quarter, full moon and last quarter.

Mother-of-Pearl: Dial material that has been cultivated from the inside of certain shells; Provides an iridescent surface and gives timepieces a rich aesthetic.

Movement: Assembly making up the principal elements and mechanisms of a watch or clock; Includes the winding and setting mechanism, the mainspring, the train, the escapement and the regulating elements.

Perpetual Calendar: Complication that exhibits the days in a Gregorian calendar, the most common calendar used today; Automatically adjusts to months with different amounts of days in them.

Power Reserve: Time a watch will continue running based on the movement's residual winding of its mainspring; In quartz and digital watches, this can also refer to the amount of energy left in the battery.

Push Button Dual Deployant: Similar to deployant clasps, with the addition of two small hidden push buttons that spring your clasp open.

Quartz Movement: Most common type of movement used in modern timepieces; Vibrating at a high frequency and placed under an electric current, quartz movements provide accurate time without the need to wind.

Repeater: Complex watch mechanism that sounds hours, quarters or minutes, or repeats them on request; Originally designed to help the wearer to tell the time in the dark.

Retrograde: Hour, minute, second or calendar hand that moves across a scale and resets to zero at the end of its cycle.

Sapphire Crystal: High-end crystal that adds greater value to a timepiece; The only natural substance able to harm a sapphire crystal is a diamond.

Skeletonization: Cutting away unnecessary metal from the movement to allow the wearer to actually see through the movement; Any part that is not needed is carved out, leaving only the movement's skeleton.

Subdial: Smaller dials located on the main dial of a timepiece; Used to measure seconds, minutes or days.

Tachymeter: Popular complication that measures distance based on speed; Typically located along the outer rim of a dial.

Water resistant: Watches described as simply "water resistant" can handle light moisture, such as a rainstorm or splashes from a sink, but they should not be completely submerged in water for any length of time; A commonly used measurement in water resistance is ATM, which stands for "atmospheres" or the amount of pressure a watch can withstand before leaking.
About Rubber:

Originally harvested by the Aztecs and Mayans thousands of years ago, natural rubber comes from the sap of wild rubber trees native to Central and South America. It is collected manually by tapping, or cutting into their bark, to free the white sap known as latex. The latex is then shipped to factories where machines make it into everyday products. Highly valued for being waterproof, polyurethane rubber is an exceptionally strong form that conveniently absorbs color. It withstands abrasive environmental forces and is UV resistant, thus making it ideal for watches that will see a variety of surroundings.