Logging refers to the process by which an Oracle Names server will note and append error-specific information to a log file. Log information is typically stored in NAMES.LOG in $ORACLE_ HOME/network/log on UNIX and ORACLE_HOME\network\log on Windows platforms.
Tracing is an additional feature that allows you to obtain more information about the internal operations of an Oracle Names server than is provided in a log file. Trace information is typically stored in NAMES.TRC server in $ORACLE_ HOME/network/log on UNIX and ORACLE_HOME\network\ltrace on Windows platforms
To enable logging or tracing: