Search engines pick one version and ignore the others, which means duplication costs you by splitting links and impressions rather than by triggering a sanction. The usual sources are mundane: http and https both resolving, www and non-www, trailing slashes, tracking parameters, print views, and syndicated product descriptions shared with every competitor.
The fix order is redirects first, canonicals second, noindex last. A 301 removes the duplicate entirely; a canonical asks nicely; noindex keeps the page crawlable but out of results. For manufacturer descriptions reused across a market, the only real answer is original content: your own photography, your own specifications, real reviews.