Oracle Basic Terminology

Oracle Server: a database management system that provides an open, comprehensive, integrated approach to information management that consists of an Oracle Instance and an Oracle database.

Oracle Instance: Consists of memory and background process structures. A means to access an Oracle database and always opens one and only one database

• Memory structures: Shared Pool (Library Chache and Data Disctionary Cache), Java Pool, Large Pool, Database Buffer Cache, Redo Log Buffer. (Note: In 10g all the memory structures are grouped under a command name SGA)
• Background Processes: PMON, SMON, DBWR, LGWR, CKPT and Others

Oracle Database: A collection of data that is treated as a unit consists of three file types:

• Physical Structure files: Data files, Control files, Redo Log files
• Parameter file: Ex:-initWORK.ora
• Archived Log files