An automated way for services in a cloud application to find and connect to each other without hardcoding addresses. Like a phone directory that automatically updates when people move — services register themselves and others look them up by name instead of memorizing addresses.
A streaming platform uses AWS Cloud Map so their video encoding, thumbnail generation, and recommendation microservices can automatically find each other as instances scale up and down, without anyone manually updating configuration files with new IP addresses.
All provide a registry where services register endpoints and clients resolve them by name. AWS Cloud Map and GCP Service Directory are dedicated service registries often paired with DNS. Azure commonly provides service discovery through Service Fabric’s built-in Naming Service (and, in Kubernetes, via CoreDNS). OCI does not have a single, direct equivalent managed service registry; service discovery is typically handled via Kubernetes DNS (OKE/CoreDNS), private DNS, or third-party tools like Consul.