The latest release version now comes packaged with the Postgre SQL DBMS installs as an optional add-on.
As of this writing Post GIS 2.2.0 is the latest stable release.
Database designers typically organize the data to model aspects of reality in a way that supports processes requiring information, such as (for example) modelling the availability of rooms in hotels in a way that supports finding a hotel with vacancies.
We will only be using the _POLY files for this exercise.
---FOR LINUX USERS --- If you are on Linux/Unix, I find the exercise even easier.
QGIS has ability to view Post GIS data both geometry and raster directly, do simple filters on it, is free, is cross-platform (Linux, Windows, Mac OSX, Unix) and is the least threatening of all the GIS Viewers I have seen out there for people new to GIS.
A relational database, more restrictively, is a collection of schemas, tables, queries, reports, views, and other elements.
Computer scientists may classify database-management systems according to the database models that they support; the most popular database systems since the 1980s have all supported the relational model - generally associated with the SQL language.