A meta tag is an HTML element placed in the head section of a web page that provides metadata about the page. Meta tags are not visible to users but are read by browsers, search engines, and social media platforms to understand the page's content, behavior, and presentation preferences.
The most SEO-relevant meta tags include the description tag (which provides a summary displayed in search results), the robots tag (which controls indexing behavior), and the viewport tag (which controls mobile rendering). While the keywords meta tag was once important for SEO, modern search engines largely ignore it due to historical abuse. HTML meta tags books on Amazon cover all standard tags.
For URL shortening services, meta tags on splash pages and preview pages are important for controlling how these pages appear in search results and social media shares. The meta description should clearly explain the page's purpose, and the robots tag should be set appropriately to prevent indexing of redirect intermediary pages.
Open Graph meta tags (og:title, og:description, og:image) and Twitter Card meta tags control how links appear when shared on social media platforms. These tags are especially important for URL shortening services because they determine the preview that users see before clicking a shared link. Social media optimization books on Amazon discuss best practices.