Hashtags play a pivotal role in social media marketing by categorizing content, enhancing discoverability, and engaging audiences. They act as keywords that users can search to find related posts, increasing the visibility of a brand's message. By using relevant hashtags, businesses can join ongoing conversations and reach target demographics effectively. Additionally, hashtags facilitate user-generated content and increase engagement, allowing brands to tap into wider communities. Overall, effective use of hashtags contributes to brand awareness, audience growth, and overall marketing strategy effectiveness.