A tablespace is a logical storage unit within an Oracle database.
Tablespace is not visible in the file system of the machine on which the database resides. A tablespace, in turn, consists of at least one datafile which, in turn, are physically located in the file system of the server.
A datafile belongs to exactly one tablespace. Each table, index and so on that is stored in an Oracle database belongs to a tablespace.
The tablespace builds the bridge between the Oracle database and the filesystem in which the table's or index' data is stored.
There are three types of tablespaces in Oracle:
▪ Permanent tablespaces
▪ Undo tablespaces
▪ Temporary tablespaces