AWS Shield is a managed DDoS protection service that safeguards applications running on AWS from distributed denial of service (DDoS) attacks. DDoS attacks are malicious attempts to disrupt the normal functioning of a website or application by overwhelming it with a large volume of traffic from multiple sources. AWS Shield provides two tiers of protection: Standard and Advanced. AWS Shield Standard is automatically enabled for all AWS customers at no additional cost. It protects your AWS resources, such as Amazon CloudFront, AWS Global Accelerator, and Amazon Route 53, from the most common and frequently occurring network and transport layer DDoS attacks. AWS Shield Advanced is an optional paid service that provides additional protection for your AWS resources and applications, such as Amazon Elastic Compute Cloud (Amazon EC2), Elastic Load Balancing (ELB), Amazon Simple Storage Service (Amazon S3), Amazon Relational Database Service (Amazon RDS), and AWS Elastic Beanstalk. AWSShield Advanced offers enhanced detection and mitigation capabilities, 24/7 access to the AWS DDoS Response Team (DRT), real-time visibility and reporting, and cost protection against DDoS-related spikes in your AWS bill12

 AWS Shield, What is a DDOS Attack & How to Protect Your Site Against One