The document discusses the difference between relevance and serendipity in recommendations. It notes that while relevance provides related items, serendipity involves an element of surprise or discovery through unexpected recommendations. Examples are given of systems that aim to provide this type of serendipitous experience, such as shuffle modes, random news recommenders, or those exposing users to alternative viewpoints. Maintaining a balance of relevance and serendipity is presented as important for keeping users informed without becoming too predictable.