What are the basic element of Base configuration of an oracle Database ?

It consists of

one or more data files.

one or more control files.

two or more redo log files.

The Database contains

multiple users/schemas

one or more rollback segments

one or more tablespaces

Data dictionary tables

User objects (table,indexes,views etc.,)

The server that access the database consists of

SGA  (Database  buffer,  Dictionary  Cache  Buffers, Redo log buffers, Shared SQL pool)

SMON (System MONito)

PMON (Process MONitor)

LGWR (LoG  Write)

DBWR (Data Base Write)

ARCH (ARCHiver)

CKPT  (Check Point)

RECO

Dispatcher

User Process with associated PGS