Dial and Hands:

Analogue indication with indexes and hands

Digital indication with figures - normally only in combination with quartz movements.
Illuminous Tritium paint on dial indexes and hands is usually indicated by the the imprint T or T25 on the dial.

Day/Date indication can be available in different languages.

Complications are additional functions of a watch, e.g. timing functions of a chronograph, these are usually indicated separately on sub dials.
Hands are available in numerous shapes, Baton, Dauphine, Breguet, lance, skeleton, etc. How the second hand moves allows concluding the type of movement behind the dial: A jumping second hand has a quartz movement behind, a sweeping second hand a mechanical movement.
 

Crystal:

Crystals must be scratch and shock resistant. The harder and more scratch resistant, the less flexible and shock resistant is a crystal. Hardness is measured on the MOH´s scale in steps from 1-10 (Fingernails = 2, Steel = 5-6, Diamond = 10). The classification is according to which material scratches another.

• Sapphire, artificially manufactured material, MOH 9 = next to diamond, extremely scratch resistant.
• Mineral glass with hardened surface, MOH 6-7 = still harder than steel.
• Plastic/Acrylic glass = PMMA = Polymethylmethacrylat, MOH 3-4, less scratch, but more shock resistant and scratches can be polished out with special acrylic polishes. Also the right material for extremely domed crystals

continue reading: Water Resistance & Chronomter