 Hello, this is Hans van der Kwas senior lecturer at IHG Delft Institute for Water Education. In this video I'm going to demonstrate the use of map themes in QGIS. Map themes are presets of combinations of layers. So here we can select several layers and we can click add theme, give it a name and then it becomes a preset. So here we call it sentinel true color where we have this true color sentinel image with the boundary polygon. Now I'm going to uncheck and check other layers and here we have the sentinel false color. I click add theme and I call it sentinel false color. Click OK. That's our second map theme. Now make one for open street map offline, add theme, call it OSM offline for example and I do the same for open street map online. Click add theme again, OSM online. Now let's check if this works. So I can click here and I see the different map themes listed and I can easily switch between them. So that's very useful if you want to show some results. Of course you can work with layer groups but this is another way of simply demonstrating combinations of layers to somebody in an organized way. If you want to see updates of these videos please subscribe to my YouTube channel. For more free materials you can also go to GISOpenCourseWare.org which is the website of the IHC Delft GIS OpenCourseWare.