the.com/preview
A trailer's worth of truth, designed to make you want the whole thing.
means An advance look at something before its official release or completion, offered to inform or tempt you.
from From Latin 'prae' (before) plus 'videre' (to see) — literally to see-ahead, the act of peeking forward in time.
Tease economyMovie trailers often spoil their own best jokes.
Tech meaningSoftware previews ship bugs you politely call features.
Word relativesShares 'videre' roots with video, vision, and evident.