Layer 7 is the application-level communication layer in the OSI network model. In networking, communication between services happens at multiple layers, ranging from the physical/hardware layer all the way to the application layer. Layer 7 is used as shorthand for the communication layer that is closest to the user. Layer 7 protocols include HTTP, gRPC, and applications-specific protocols such as Redis and Kafka.
Today's cloud-native applications generally manage communication at Layer 7. Thus, proper Layer 7 traffic management and control is crucial to the availability and performance of cloud-native applications.