Quality data is the first step to creating informative maps.  In Surfer you can download data from four different types of servers, each of which provides a different type of data:

1. WMS servers: These servers provide image files (e.g. TIF), and you can use them as base maps or as grid-files (although there are no real world Z values). It’s just an image. Many of the images provided are satellite or aerial photography, but they could also be images of boundaries or point locations. The default WMS servers are in the US Imagery and Worldwide Imagery categories.
2. OSM servers: Like WMS servers, these servers provide image files and are best used for base maps. Many of the images provided are maps including roads, streets, and boundaries. 
   There are no default OSM servers at this time but you can add them yourself by following the instructions in this article: Add a WMS, OSM, WFS, or WCS server to Surfer
3. WFS servers: These servers provide vector files (e.g. GML), and you can use them to create base maps only. They’ll import points, polylines and polygons. The default WFS servers are in the US Vector Data and Worldwide Vector Data categories.
4. WCS servers: These servers provide grid data, and you can use them to create any grid-based maps. They’re grid files, and so you can only create grid-based maps from them. There are no default WCS servers at this time but you can add one yourself by following the instructions in this article: Add a WMS, OSM, WFS, or WCS server to Surfer.

Updated May 2023