Automatic Movement
Automatic watches are the movements that do not require battery. Rather than the battery as a power source for the movement, the self winding movement from kinetic motion powers the watch for the life of the watches. Typically but not always, the automatic watches are thicker in case and slightly heavier.

Bezel
The bezel is the ring portion of a watch around the crystal. Depending on the watch, the bezel may be plain, or has markers and numbers on the bezel. Some watches come with unidirectional rotating, where the bezel can be rotated.

Bracelet
Bracelets are none leather or none metallic materials that are used to wrap around a person's wrist. The bracelets can come in Titanium, stainless steel, rubber, and other form of materials.

Case
The case refers to the body of a watch. The case is important in that it protects the central movement of the watches from exposure to environment and tempering.

Chronograph
Chronographs are watches that have additional sundials on the face of the watches. These subdials are typically used to measure hours, minutes, and seconds as a stop watch. 

Chronometer
Chronometer refers to watch movements that have been certified. These certified moments are passed through rigorous tests for accuracy. The coveted tests are performed by the C.O.S.C. in Switzerland. Such watches contain a certificate attesting to this from the institute.

Crown
The “crown” refers to the knob on the outside of the watchcase, which is used to wind the watch. The crown is also used for many other functions such as to set the time and calendar date. 

Deployment Clasp
This refers to a buckle that connects the two ends of the watchband at all times. The wearer deploys the buckle to put the watch on and then fastens it securely onto the wrist. When the clasp is fastened, the buckle hides the deployment mechanism.

Dial
The “dial” refers to the face of the watch and is a term usually used when referencing the color. A dial may contain smaller “sub-dials” for seconds, minutes, or hours (see chronograph).

End of Battery Life Indicator
This feature is an indicator that the batteries are running low on the watches. Generally, the second hand will start ticking in 5 second increments instead of the normal one second at a time.

Link
The “links” are the individual metallic pieces that connect to form the bracelet.

Movement
The movement refers to how the watch operates. The movement is the mechanism that keeps the time running. Movements are either quartz or automatic.

Quartz Movement
Quartz movement watches are watches that require battery, and the standard watches use quartz technology. The average life span of a battery is 2-3 years.

Sapphire Crystal
The “crystal” is the covering on the face of the watch. Sapphire crystals are scratch resistant and are less prone to breakage then standard mineral crystals. In general, luxury watches contain the more expensive, sapphire crystal.

Strap
A strap refers to a watchband made of none metallic and instead from leather, plastic, or a generic fabric.

Unidirectional Bezel
This bezel can move in one direction and is used for mathematical and time past uses.

Water Resistant
Unless otherwise specified, water resistant watches can safely withstand minimal contact with water (i.e. getting splashed from the sink faucet). Most watches contain this feature.
Some watches will specify that they are water resistant up to 30 meters and some may go up to 1000 meters. This means that the watch can be completely submerged up to the stated depth without damage.