What are the differences between volumetric and application-layer DDoS attacks, and how should I protect against each?

Volumetric attacks (e.g., UDP floods, SYN floods) overwhelm network bandwidth. Protection involves using CDNs, reverse proxies, and DDoS mitigation services that can absorb large volumes of traffic. Application-layer attacks (e.g., HTTP floods) target specific application vulnerabilities. Protection requires WAFs, rate limiting, CAPTCHAs, and input validation to filter malicious requests.