I am writing some training notes for new QGIS users at my work.
I have a section on types of vector files; ESRI Shapefile, MapInfo Tab and GML & GZ so far.
We sometimes use the UK Land Registry INSPIRE polygons, supplied as .gml, and Ordnance Survey MasterMap supplied as .gz
So I have written a paragraph on shapefiles and Tab files, but have struggled to come up with anything succinct for GML files. I have tried to understand the Wikipedia entry Geographic Markup Language so I understand that it is markup language for geographic information, as the name obviously implies.
But then the details require a degree of technical understanding that I am finding pretty impenetrable.
I have had a look at other web pages as well and they all more or less say the same thing, even the GIS Stackechange tag for gml that says "Geography Markup Language (GML) is an OGC Standard for expressing geographical features" - doesn't, to my mind, shed any light.
Also the question What does it mean "GML is an XML grammar"? goes over my head.
I am looking for a short paragraph that explains what it is for a new user (and myself clearly)
The best I can come up with at the moment is...
GML is a vector file format that allows for geographic data to be kept as a text file that can be shared easily between systems
It's easy enough to open a GML file in QGIS, and work with it, so perhaps this explanation more or less be skipped over anyway, but then how does a GML get created, in what software? I'd be looking for this to be included as part of the answer.
Or am I overcomplicating it?