What does a canonical URL help to avoid?

A canonical URL helps to avoid duplicate content penalties. When multiple URLs can access the same content, search engines may struggle to determine which version should be indexed and ranked. This can lead to issues where pages compete against one another for visibility, diluting their ranking potential. By specifying a canonical URL, you indicate to search engines which version of the content is the preferred one, thereby consolidating the ranking signals and helping to prevent the negative impacts associated with duplicate content. This practice is crucial for maintaining SEO performance and ensuring that your site's content is correctly indexed.