You can configure primary and backup nodes for MRS, DIS, and Scheduler services which helps in handling the requests if the service running on primary node A (Active) goes down and the service will be up and running in the backup node B (Passive).
Other services CMS, Analyst, and Search does not support High Availability. You have to manually switch the node configuration for these services using the Admin Console or command line and then bring up the services respectively.
Informatica uses the terminology keyword "High Availability" for service failover and the keyword "Grid" for the load balancer.
Refer to High Availability Overview for details about High Availability.