We can activate labeling by going to Layer Properties | Labels, checking the Label this layer with box, and selecting the attribute field that we want to use for the labels. This is all we need to do to display labels with default settings. While default labels are great for a quick preview, we would usually want to customize the labels if we create visualizations for reports or standalone maps.
Using Expressions (the button that is right beside the attribute drop-down list), we can format the label text to suit our needs. For example, the NAME field in our sample
airports.shp file contains text in uppercase. To display the airport names in mixed case instead, we can set the
title(NAME) expression; this will reformat the name text in title ...