AWS ALB, or Amazon Web Services Application Load Balancer, is a service that provides intelligent and flexible load balancing for your web applications. AWS ALB is a Layer 7 load balancer, which means it operates at the application layer (HTTP/HTTPS) of the OSI model. It is designed to distribute incoming web traffic across multiple targets, such as Amazon EC2 instances, containers, or IP addresses, to ensure high availability and fault tolerance for your web applications.