Buttons in the toolbar usually display icons instead of text. To implement this, we need to add icon files to our project and assign them to the actions we created.
One way of creating icons is by loading images from the filesystem. The problem with this is that you have to install a bunch of files along with your application, and you need to always know where they are located to be able to provide paths to access them. Fortunately, Qt provides a convenient and portable way to embed arbitrary files (such as images for icons) directly in the executable file. This is done by preparing resource files that are later compiled in the binary. Qt Creator provides a graphical tool for this as well.