Canonicalization

Canonicalization is what Google does behind the scenes when duplicate URLs exist — it clusters them and picks one representative to index and rank. Your rel=canonical tag is a strong hint in that decision, but Google weighs it against internal links, redirects, sitemap entries, and hreflang, and it will overrule you if those signals conflict. Keep every signal pointing at the same URL — consistent protocol, trailing slash, and casing — or Google may canonicalize to a version you didn't intend and drop the rest.