[postgis-users] Where can I find the documentation to SQL shell (psql)?

[Henri De Feraudy]

Hello,
 I just installed PostgreSL on windows XP. Now if I click on the Start button and then on Programs and then PostgreSQL 8.4 one of the items is "SQL shell (psql)".
I cant find the documentation to this. In the document called PostgreSQL 8.4.1 documentation there is no occurrence of the word "Shell".
Henri