When working with GIS data, you might want to delete certain features or run your query on a subset of features from a layer. There are many methods available that can help you save time and select a large number of features easily. I will cover some of these in this tutorial. Make sure you enable the ‘Attributes’ toolbar for easy access to some of the selection tools. Right click on any empty space on the toolbar area and turn on the checkbox. A lot of selection tools are available under the Selection menu. You can access this via the toolbar as shown below or by going to View → Select. You can choose any one of them and click on the canvas to draw a shape and select features that intersect the shape. Most of these are obvious, but we can try ‘select features by freehand’ for an example. Select it and draw a shape while holding your left mouse button. Release the button when you are done and you will see a selection appear on screen. Another way to make multiple selection is holding down the Ctrl key and making the selection. You can use any selection method for this. Let’s use the ‘select single feature’ method. Choose that and click on other features that you want to select while holding down the Ctrl key. This will add these features to your selection. for a detailed step-by-step guide on attribute table.) For example, if you wanted to select all countries in the world which started with the letter ‘A’ or ‘B’. This can be easily accomplished by using the Query Builder. Open the Attribute Table for the layer by going to Layer → Open Attribute Table. Formulate your query. We can use the % wildcard along with LIKE operator to specify our query. Enter the query and click OK. These were some of the ways of selecting multiple features in QGIS. If you are working with multiple layers, you can also use Spatial Queries to make selection based on features in another layer. Source.