Automatic Watch
Automatic watches are mechanical watches that are self-winding. The movement of your wrist and body causes the rotor, (a weight attached to an automatic winding mechanism), to wind up the watch. Automatic watches do not need batteries. However, automatic watches will stop if not worn for over a day, or if you have been physically inactive for an extended period of time.

Bezel
The bezel is the outer ring of the case that holds the crystals in place. Many sport watches feature bezels that rotate to allow divers to safely measure how long they've been under water.

Chronograph
Chronographs are timepieces that also operate as stopwatches. They permit the measurement of a desired interval time, and feature start/stop/reset functions. An Invicta chronograph can measure time within intervals of 1/60 of a second.

Dial
The dial, often referred to as the face is usually marked with numbers or batons to which the hands point in order for the wearer to tell the correct time. Dials may be minimalist with no markers at all or extremely complex as in the case of pilots' chronographs. Dials may be decorated with patterns or in some cases with precious stones.

Jewels
Jewels are the ruby stones that a watch's gear turn on to protect the metal parts from grinding together.

Mechanical Watch
Mechanical watches do not use batteries, yet they are more than accurate enough for daily use. In fact, a good mechanical watch is often more accurate over a short period of time than a quartz watch. Mechanical watches are very durable, and are often handed down from generation to generation.

Mother-of-Pearl
Iridescent milky interior shell of the freshwater mollusk that is sliced thin and used on watch dials. While most have a milky white luster, mother-of-pearl also comes in other colors such as silvery gray, gray blue, pink and salmon.

Quartz Watch
Watches with quartz movement do required the use of batteries as a source of power. These batteries typically last from 12-18 months. The accuracy of these watches depends a great deal on the precision of the angle of cut of quartz (silicon dioxide) sheet with respect to the crystalline axis. Most common watches have quartz movement.

Rose (or pink) Gold
A softly hued gold that contains the same metals as yellow gold but with a higher concentration of copper in the alloy. A popular color in Europe, rose gold in watches is often seen in retro styling or in tricolor gold versions. Some 18k rose gold watches achieve their color from additional copper in the alloy.

Rotating Bezel
A bezel that can be turned. Different types of rotating bezels perform different timekeeping and mathematical functions.

Screw-Down Locking Crown
A crown that aids water resistance by sealing the crown to the case of the watch. The seal is achieved by the matching of a threaded pipe on the case with the crown's internal threads and gaskets, while twisting the crown to lock it into place.

Self-Winding
This term refers to a mechanically powered watch that is wound by the motion of the wearer's arm rather than through turning the winding stem (manual mechanical). In response to this motion, a rotor turns and winds the watch's mainspring. Most automatic watches have up to 36 hours of power reserve. If an automatic watch is not worn for a day or two, it will wind down and need to be wound by hand to get it started again.

Shock Resistance
As defined by the U.S. government regulation, a watch's ability to withstand an impact equal to that of being dropped onto a wood floor from a height of three feet.

Stainless Steel
An extremely durable metal alloy (chromium is a main ingredient) that is virtually immune to rust, discoloration, and corrosion; it can be highly polished, thus resembling a precious metal. Stainless steel is often used even on case backs on watches made of other metals and is the metal of choice used to make high quality watchcases and bracelets. It is also hypoallergenic because it doesn't contain nickel.

Subdial
A small dial used for any of several purposes, such as keeping track of elapsed minutes or hours on a chronograph or indicating the date.

Titanium
A "space age" metal, often having a silver-gray appearance. Because it is 30 percent stronger and nearly 50 percent lighter than steel, it has been increasingly used in watch making, especially sport watch styles. Its resistance to salt water corrosion makes it particularly useful in diver's watches. Since it can be scratched easily, some manufacturers use a patented-coating to resist scratching. Titanium is also hypoallergenic.

Unidirectional Rotating Bezel
An elapsed time rotating bezel, often found on divers watches, that moves only in a counterclockwise direction. It is designed to prevent a diver who has unwittingly knocked the bezel off its original position from overestimating his remaining air supply. Because the bezel only moves in one direction, the diver can err only on the side of safety when timing his dive. Many are ratcheted, so that they lock into place for greater safety.

Water Resistance
Describes the level of protection a watch has from water damage. See the "water resistance" section for a description of the different levels.