Component
Component is a part of the service. For example, HDFS service consists of the following components: Client, DataNode, JournalNode, HttpFS server, NameNode, ZKFC. Breaking a service down into components makes it easier to work with the complicated cluster software. You can see the components of a service on the Components tab of the page of that service inside the Services subsection.
Components tab in ADCM
The set of components depends on the bundle that is used to deploy a cluster. After cluster is created and necessary services are added, you can choose components in the Mapping subsection.
Mapping subsection in ADCM