What is Firebase Storage?
Answer
Firebase Cloud Storage is Google Cloud Storage integration optimized for Firebase apps. It stores user-generated content — images, videos, audio files, documents — and provides client-side SDKs for uploading and downloading directly from the browser or mobile app. Key features: (1) Security Rules — Firebase Storage Security Rules control read/write access based on authentication state and custom conditions; (2) Resumable uploads — large file uploads automatically resume if interrupted; (3) Download URLs — generate temporary or permanent download URLs for files; (4) Progress monitoring — upload/download progress events for progress bars; (5) Multiple buckets — use different storage buckets for different data types or regions; (6) CDN integration — files are served via Google's global CDN. Common use cases: user profile pictures, document storage, media uploads. Cloud Functions can trigger on file upload to resize images, extract metadata, or perform virus scanning.