Managing duplicate content on Joomla involves implementing various strategies. We use canonical tags to specify the preferred version of a page when duplicate content exists. Additionally, we avoid content duplication by setting up proper redirects for similar or identical content, optimizing category and tag pages, and utilizing the noindex meta tag for non-essential pages. Regular content audits, unique meta titles and descriptions, and using tools to identify and resolve duplicate content instances are crucial in preventing content duplication issues.