Beginner's question about ODBC and/or foreign data sources

Greetings.

I have installed and used PostgreSQL at a beginner's level (simple
database creation, simple PHP website querying) and would love to use it
at work to complement and/or (hopefully) replace Access as our software
of choice.

Anyhow, I'm trying to find information on how to connect PostgreSQL to
an ODBC data source.  I've seen a lot of information on connecting TO
PostgreSQL from other (ODBC) sources, but I can't locate a clear
description of how to access data FROM ODBC sources to query within
PostgreSQL.  I have software which offers Windows ODBC drivers, but need
to get at it from PostgreSQL.

I may be entirely misunderstanding the ODBC issue, but it seems that
the PostgreSQL ODBC drivers are for connecting TO PostgreSQL, and not
what I am trying to accomplish.

Do I need to be messing with/foreign data wrappers here?

Thank you for your patience with this silly question!
George R.