Use this technique when you need to eliminate existing copy pages. All redirection methods —301 and 302 redirects, meta-refresh, JavaScript redirects—have the exact same impact on Google Search, on the other hand enough time it will take for search engines like yahoo to note the several redirect strategies might differ. https://addons.prestashop.com/es/seo-posicionamiento-buscadores/30904-etiquetas-automaticas-hreflang-canonical-etiquetas-seo.html