Watch terminology: calibres, GMT, chronographs and seller labels

Movement, calibre and decoration

Movement: The mechanism that powers the hands and any calendar or additional functions. Its identity is separate from the model name on the dial.
Calibre: A maker's designation for a movement design or version. In a replica description, establish whether it names the actual mechanism or the genuine reference design.
Base movement: The underlying mechanism when other parts or modules have been added. A decorative bridge or rotor inscription does not by itself change the identity of that base.
Automatic and manual winding: An automatic movement winds through its rotor; whether it also supports hand winding depends on the calibre. A manual movement relies on hand winding. Control instructions must match the actual calibre.

Read the movement-label guide before treating a stamped number as identification.

Beats per hour, BPH or VPH: Common listing shorthand for balance beats or vibrations per hour. A frequency of 28,800 beats per hour is eight beats per second, corresponding to four full oscillations per second, or 4 Hz. Frequency does not establish origin or accuracy.
Power reserve: The time a fully wound mechanical movement can continue running without further winding. A published reference figure and a recorded result for an individual watch are different information.
Rate: How much a watch gains or loses over a stated time interval. A useful result includes the interval and conditions; one brief observation is not a long-term accuracy record.

The ETA reference table keeps movement versions and specification revisions separate.

Quickset date: A control that adjusts the calendar without repeatedly advancing the main time display. The allowed operating times depend on the movement's instructions.
Ghost date position: An extra calendar-setting crown position on a watch without a visible date. It can indicate a calendar-equipped base under a time-only dial; its presence alone does not prove a fault.
GMT or 24-hour hand: A hand that makes one circuit in 24 hours and is read against an appropriate scale. Its adjustment method must be demonstrated rather than inferred from the dial.
Jumping local hour: An hour hand that moves in one-hour steps independently of the minute hand in the relevant setting mode. This is useful for changing local time while retaining a home-time reference.

Use the GMT function comparison for a worked time-zone example.

Chronograph: A start, stop and reset timing function. A watch with three subdials does not necessarily provide three elapsed-time counters.
Running seconds: The ordinary seconds display, which can continue while a separate central chronograph hand is stopped.
Elapsed-time counter: A register that totals chronograph minutes or hours. A short video may demonstrate the seconds hand without establishing how an hour counter behaves.
Tachymeter: A scale used to convert a measured elapsed time over one unit of distance into a rate per hour. It does not measure speed without a known distance and timed interval.

The Daytona guide provides a counter observation matrix; the 7750 guide explains a named reference mechanism.

Gold colour, plating and solid gold: These describe different things: an appearance, a surface treatment and a material composition. Colour and total watch weight are insufficient to establish precious-metal content.
Water resistance: A property of the assembled watch under stated conditions. A printed depth marking or the genuine model's rating is not a test of a replica's seals.
AAA, 1:1 and super clone: Seller descriptions with no uniform specification established by those words alone. Replace the grade with actual construction, functions and evidence in a comparison.

Record matched, mismatched and unverified points separately in the quality checklist.