QGIS: Your Free Professional GIS

Open QGIS and the first job is to stop being intimidated. The window is only four things.

Across the top are the menus and toolbars - every tool lives here, and you can ignore 90% of them for weeks. Down the left are two dockable panels: the Browser, which is a file-explorer for spatial data (your folders, GeoPackages, XYZ tile sources, PostGIS databases), and the Layers panel, which lists what is currently in your map. The big area in the middle is the map canvas - where the map actually draws. Along the bottom is the status bar, and the single most important thing on it: the project CRS (coordinate reference system), sitting in the bottom-right corner where you should glance at it constantly.

That is the whole interface. Panels can be dragged, closed and reopened (View menu, Panels), but the layout is the same on Windows, macOS and Linux, so a skill learned on one machine transfers to any other.

Almost everything you do in QGIS, you do through the Layers panel. Each dataset you add becomes a row. The checkbox turns it on and off. Double-clicking opens its Properties - style, labels, the CRS it is stored in, its metadata. Right-clicking gives you the everyday verbs: Zoom to Layer, Open Attribute Table, Export, Remove.

The one rule that trips up every beginner is draw order. Layers draw from the top of the list down, so the layer at the top of the panel is painted last and sits on top in the canvas. Put an opaque satellite image at the top and it hides everything beneath it; drag it to the bottom and your roads and plots reappear over it. If a layer you just added seems to have vanished, it has almost certainly not vanished - something above it is covering it. Reordering the list, not re-loading the data, is the fix.

The Browser panel is how you avoid the File-Open maze. It shows a tree of data sources - your home folder, saved connections, and crucially XYZ Tiles (web base maps) and database connections. Expand a GeoPackage and you can see the layers inside it; drag any of them straight onto the canvas.

For a first map you rarely need a downloaded file at all. Two Browser tricks cover most starts. First, add an XYZ tile base map - a web imagery or street layer that streams in as you pan. Second, pull real vector data with the free QuickOSM plugin, which queries OpenStreetMap and drops the result in as a proper, clickable layer. Between a tile base map and an OSM query you can build a useful map of any Indian city in minutes, with no data licence to chase - a genuine advantage when public datasets are scattered or gated.

"Free" is not the interesting part; open is. QGIS is a friendly interface sitting on top of the same open engines that power most of the GIS world - GDAL/OGR (reads and writes hundreds of formats), PROJ (does the coordinate maths) and GEOS (does the geometry). Because these are open, QGIS reads almost anything, including Esri formats, and your work is never locked inside one vendor's file that you must keep paying to open.

For a student, this means you learn on the exact tool you will use in practice, with no time-limited trial. For a not-for-profit or a small studio, it means putting professional GIS on every machine without a per-seat bill. And because it is extensible through plugins (QuickOSM for data, the Semi-Automatic Classification Plugin for imagery, qgis2threejs for 3D web export, and the GRASS and SAGA processing providers for heavy analysis), QGIS grows with you instead of hitting a paywall at the next feature. The LTR - Long Term Release - line, currently 3.44 'Solothurn', is the stable version to install for real work.

Knowing the panels, a first map is a short sequence: set a sensible project CRS (a metre-based one over your site if you will measure anything), add a base map from the Browser's XYZ Tiles, pull an OSM layer with QuickOSM, tidy the draw order so your data sits over the imagery, then click a feature with the Identify tool to read its attributes. That last click - shape to data row - is the moment GIS stops being a picture and becomes a question you can ask.

Save the result as a QGIS project (a .qgz file). The project does not contain the data; it remembers which layers, in what order, styled how, in which CRS. Reopen it tomorrow and your map returns exactly as you left it. The workshop below walks this end to end.