When you install the Informatica services on a machine, you create a node and a domain. You can install the Informatica services on multiple machines to create additional nodes that you join to the domain.
A single node installation consists of a domain with one node. The node hosts the domain. The Service Manager and all Informatica application services run on the node.
An installation on multiple nodes consists of a gateway node, which hosts the domain, and additional nodes that run Informatica application services. The Service Manager runs on all nodes in the domain.
The following image shows an installation on multiple nodes: