In a cloud environment where docker images are dynamically deployed on any machine or IP + Port combination, it becomes difficult for dependent services to update at runtime. Service discovery is created due to that purpose only. Service discovery is one of the services running under microservices architecture, which registers entries of all of the services running under the service mesh. All of the actions are available through the REST API. So whenever the services are up and running, the individual services registers themselves to service discovery service and service discovery services maintains heartbeat to make sure that those services are alive. That also serves the purpose of monitoring services as well. Service discovery also helps in distributing requests across services deployed in a fair manner.