In the digital age, video streaming dominates content consumption but faces challenges like buffering and latency, which CDNs help resolve by distributing content through geographically dispersed servers. CDNs improve performance using edge caching, load balancing, and adaptive bitrate streaming. They also boost scalability during traffic spikes and add security with DDoS protection and DRM. Costs can be high, and issues like compliance and cache invalidation exist. Best practices include selecting a CDN with global coverage, using ABR, optimizing encoding, and leveraging prefetching. Future trends include edge computing, 5G, AI-powered optimization, and serverless architectures. Proper CDN implementation is essential for providing a smooth, secure global video streaming experience.