An influencer is a person who has the power to affect the purchasing decisions of others due to their authority, knowledge, or relationship with their audience. They often share content on social media platforms like Instagram, YouTube, or TikTok, where they engage with followers and promote products or services. Influencers can be categorized into different types based on their audience size, such as macro-influencers with large followings or micro-influencers with smaller, niche audiences. Brands often collaborate with influencers to reach specific demographics and enhance their marketing strategies.