[SQL] Coming from Oracle SQL

[Veronica L Bounmixay]

I have a dumb question to ask - as I'm certain all of my future ones will be as well.  I am coming from the Oracle SQL PL/SQL side of things and trying to get wrapped around PostgreSQL.  I used to find tables in Oracle by using the following query and hoped to find a replacement.  Better would be someplace to reference these sorts of "key" tables, etc that keep track of the indexes, tables, columns and more.

select distinct table_name from all_tables;

Thank you for the help - you will never know how appreciated it is!
Ronni