Does PostgreSQL implement Geospatial relationship queries?

My company is looking at different database providers, and how they implement Geospatial queries to get distances from a Lat/Long for a number of records.

We are going to investigate PostgreSQL as a potential database platform.

• I've heard that PostGRE implements Geospatial queries. Is this correct?
• Is there a good reference somewhere that gives info on the implementation?

From stackoverflow

• It's PostGIS. For reference you have manual, wiki and more...

  ninesided : +1 beat me to it!

  vartec : I've upvoted you too ;-)

  Kent Fredric : +1 to both of you. <3 postgres to death.

• If you want to spatially enable a PostgreSQL database you can do so with PostGIS, it's compliant with the Open Geospatial Consortium's Simple Features Interface Standard for SQL too.