Social media refers to digital platforms that facilitate the creation and sharing of information, ideas, and other forms of expression via virtual communities and networks. It includes websites and applications that offer various interactive functions, such as messaging, commenting, and content sharing. 

Social media is used for a wide range of purposes including personal communication, professional networking, education, marketing, and news dissemination. Platforms like Facebook, Instagram, Twitter, LinkedIn, and TikTok are among the most popular, each serving different social interaction needs and audience demographics.