PostgreSQL 7.4.2 new tables [Stupid Query]

Dear all,

Just migrated to PostgreSQL 7.4.2 from 7.3.4

I found that  after migration to 7.4.2  some of the tables in my
database  which were not  created by me exists their
Namely :
1. information_schema.sql_features
2. information_schema.sql_implementation_info
3. information_schema.sql_languages
4. information_schema.sql_packages
5  information_schema.sql_sizing
6. information_schema.sql_sizing_profiles

These tables are viewable only with the psqlODBC connected clients i.e
when I connect to database with
psqlODBC then only these tables are viewable.

My Stupid question is  :
1. Is this normal.
2. If this is normal then what are these tables for ?

Machine Spec:
RH 9.0
PostgreSQL 7.4.2

--
Best Regards,
Vishal Kashyap
Director / Lead Developer,
Sai Hertz And Control Systems Pvt Ltd,
http://saihertz.rediffblogs.com
Jabber IM: vishalkashyap@jabber.org
ICQ :      264360076
Yahoo  IM: mailforvishal@yahoo.com
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You yourself, as much as anybody in the entire
universe, deserve your love and affection.
- Buddha
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pgsql=# select marital_status from vishals_life;

marital_status
------------------
Single not looking

1 Row(s) affected

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                  ( 0_0 )
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