Social media are interactive technologies that facilitate the creation, sharing and aggregation of content (such as ideas, interests, and other forms of expression) amongst virtual communities and networks. Common features include:

• Online platforms enable users to create and share content and participate in social networking.
• User-generated content—such as text posts or comments, digital photos or videos, and data generated through online interactions.
• Service-specific profiles that are designed and maintained by the social media organization.
• Social media helps the development of online social networks by connecting a user's profile with those of other individuals or groups.

The term social in regard to media suggests platforms enable communal activity. Social media enhances and extends human networks. Users access social media through web-based apps or custom apps on mobile devices. These interactive platforms allow individuals, communities, businesses, and organizations to share, co-create, discuss, participate in, and modify user-generated or self-curated content. Social media is used to document memories, learn, and form friendships. They may be used to promote people, companies, products, and ideas. Social media can be used to consume, publish, or share news.

Social media platforms can be categorized based on their primary function.

• Social networking sites like Facebook and LinkedIn focus on building personal and professional connections.
• Microblogging platforms, such as Twitter (now X), Threads and Mastodon, emphasize short-form content and rapid information sharing.
• Media sharing networks, including Instagram, TikTok, YouTube, and Snapchat, allow users to share images, videos, and live streams.
• Discussion and community forums like Reddit, Quora, and Discord facilitate conversations, Q&A, and niche community engagement.
• Live streaming platforms, such as Twitch, Facebook Live, and YouTube Live, enable real-time audience interaction.
• Decentralized social media platforms like Mastodon and Bluesky aim to provide social networking without corporate control, offering users more autonomy over their data and interactions.

Popular social media platforms with over 100 million registered users include Twitter, Facebook, WeChat, ShareChat, Instagram, Pinterest, QZone, Weibo, VK, Tumblr, Baidu Tieba, Threads and LinkedIn.