Often, there are multiple ways to retrieve the data. Depending on your usage of the data, the preferred method may vary.
Download: directly download the dataset. Often the data is zipped, you can use the freely available 7-zip (or many other tools) to unzip the files.
Link: these links refer to a website or web-services (for advanced users).
Sometimes a link refers to a web service. The two main web services for geographical information are WMS and WFS.
- WMS (Web Map Service): a web map service is an interface to provide geographical images of a geospatial database. Many spatial web applications, such as Google Maps, use WMS to show the maps.
- WFS (Web Feature Service): a web feature service is an interface to exchange vector format geographic information through the web. This can be very useful, as often geographical datasets are very large and you only want to download part of the dataset.
The difference between WMS and WFS is that images are served by WMS, whereas WFS communicates geographic feature information.
