Tracing produces a detailed sequence of statements that describe network events as they are run. Tracing an operation enables you to obtain more information about the internal operations of the components of Oracle Net Services than is provided in a log file.
Each Oracle Net Services component produces its own trace file. To enable tracing on the oracle client, the configuration file which needs to be modified is sqlnet.ora. This file can be found in ORACLE_HOME\network\admin directory.
Oracle Net Manager is a component/tool installed while installing Oracle client. It enables you to configure Oracle Net Services for an Oracle home on a local client or server host.