A
Directory Structure

x:\oracle_ base				c:\oracle is the default ORACLE_BASE directory
	\%ORACLE_HOME%			\ora81 is the name of the Oracle home by default
		\bin		Subtree for Oracle binaries
		\network		Subtree for Net8 configuration files, including tnsnames.ora, listener.ora and sqlnet.ora
		\ops		Files created by Oracle Database Configuration Assistant
		\opsm		\admin subdirectory
			\admin	Oracle Parallel Server ops.sql script and initialization parameter files for database creation
		\database		This is a legacy directory from previous releases. It contains initialization files that point to the new directory location for the initialization parameter files, ORACLE_BASE\admin\db_name\pfile.
		...
	\admin			Subtree for Oracle Parallel Server database administration files
		\db_name		db_name database administration files for the instance identified by SID.
			\adhoc	Ad hoc SQL scripts
			\adump	Audit files
			\arch	Archived redo log files
			\bdump	Background process trace files
			\cdump	Core dump files
			\create	Programs used to create the database
			\exp	Database export files
			\pfile	Initialization parameter files
			\udump	User SQL trace files