A tablespace is a database concept and refers to a storage location where the actual data underlying database objects can be kept.
A tablespace is a storage location where the actual data underlying database objects can be kept. It provides a layer of abstraction between physical and logical data, and serves to allocate storage for all DBMS managed segments. (A database segment is a database object which occupies physical space such as table data and indexes.)
Once created, a tablespace can be referred to by name when creating database segments. Tablespaces specify only the database storage locations, not the logical database structure, or database schema. For instance, different objects in the same schema may have different underlying tablespaces. Similarly, a tablespace may service segments for more than one schema. Sometimes it can be used to specify schema as to form a bond between logical and physical data.