Application Load Balancer (ALB) allows content-based routing, also known as request-level (Layer 7) routing, which includes the ability to route requests to different backend services based on the content of the HTTP request (such as URL path, host, and headers). Classic Load Balancer operates at both the connection level (Layer 4) and request level (Layer 7), but it does not offer advanced request routing capabilities such as host-based or path-based routing provided by ALB. Network Load Balancer operates at the connection level (Layer 4) and is optimized for low latency and high throughput but does not have the intelligent routing capabilities at the Layer 7. Amazon CloudFront, while distributing traffic, is a Content Delivery Network (CDN) service that primarily caches content rather than providing content-based routing to backend systems.