A beginner-friendly guide to Open Graph and Twitter Card meta tags: what each one does, how their syntax differs (property vs. name), and when you need both for link previews on platforms like Slack, LinkedIn, and X. Includes how to add both through the Next.js 16 Metadata API, recommended image sizing, and how to debug cached previews. Published on DevStacked, my developer blog covering practical Next.js and SaaS implementation guides.