Temporary space....

I have few confusions:

1. In my temporary tablespace, space not getting released even if the user has finished with the work. Ideally once the user using temporary tablespace, finished the job, space in the temporary tablespace used by the user should be released. But its not. Any idea why?
2. whats the diff between the two commands: create tablespace temp datafile .......... temporary; create tablespace temp tempfile .......... temporary.

Thanx in advance

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Thanks & Regards,
T. Onkar Nath
Ph : +91-9826728111(Cell)

       to_onkar_at_yahoo.com
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