The zLocal and zRemote handle the TCP/IP connection between the mainframe and the Dynatrace ActiveGate. The zLocal installs on the mainframe and passes data to the zRemote, reducing CPU consumption on z/OS.
The zLocal can't directly connect to an Dynatrace ActiveGate without first going through a zRemote. Using the zRemote reduces CPU consumption on z/OS by offloading most of the OneAgent processing.
The zLocal only transfers data to the zRemote, which can run on Windows or Linux (64-bit OS only).