Physical Storage Structure
Physical storage structure include data file, control files, Redo files.
PSS are viewable at the operating system.
Data File
Store the data
This is main file of an oracle database. The file is decided by DBA, so DBA can add data file at any time as for the requirement and change the size of data file any time and delete a data file if no required so that it is not an a parcel of that Database management .
Control File
It is does not store data ,but store controlling information about database like Database name, Database Id, Database creation, timestamp, Redo log file, Archiving check points, backup etc.
Redo File
It is store redo data.
Redo data nothing but a description of changes made to the database.
Ex
When you store the inside database you not only store the data but also modified the data from time to time. Any modification were done to the database are recorded separately in the redo log file. So modification are these changes made up the database is also called so.
This redo data is used during a recovery to apply the changes.(REDO means do again)