What are the different layers of a DDoS attack, and how does AWS protect against each?

DDoS attacks operate at three layers: Application (Layer 7), Transport (Layer 4), and Network (Layer 3). AWS Shield Standard protects against Layer 3 and 4 attacks. AWS Shield Advanced enhances protection at these layers and adds protection against Layer 7 attacks. AWS WAF specifically targets Layer 7 attacks. CloudFront helps mitigate attacks at all layers by distributing traffic and caching content.