Zombie pages are web pages on a site that generate little to no traffic, offer minimal value, and negatively impact SEO performance. They are often characterized by outdated content, broken links, or being non-responsive on mobile devices. Identifying and addressing zombie pages is crucial for improving site health, as they can dilute a website's focus and authority, leading to lower search engine rankings. Strategies to manage these pages include updating content, improving user experience, or removing them entirely. Regular audits are essential to prevent the accumulation of zombie pages and maintain optimal website performance.