Powerful GIS systems like ArcGIS are usually available at a premium and QGIS is a free, open source alternative to these enterprise level systems. QGIS comes as a suite of software that includes a Desktop GIS, a browser based GIS, a server for serving WMS and WFS services, a web client and an mobile Android version.
One of the differences out-of-the-box is that Esri provides its own basemaps whereas QGIS does not. However, a simple solution to this is to use the OpenLayers plugin in QGIS to load basemaps from Google, Bing or one of the other online map services. This can be easily installed from the plugins menu in QGIS.
Harvard provides a useful QGIS workshop that walks you through using QGIS 2.0. Try adding a basemap and then adding points from a CSV file.
The shapefile format (.shp) is a popular geospatial vector data format for geographic information system (GIS) software. It is developed and regulated by Esri (of ArcGIS fame) as a (mostly) open specification for data interoperability among Esri and other GIS software products. QGIS supports the loading of .shp files.
If we were interested in adding a layer to our GIS which includes the locations of all the ports in the World Port Index, we could download the shapefile from the National Geospatial Intelligence Agency's site and load it into the GIS software.