I believe it is simply a tool to create bar codes and QR codes. Select the type of code to create, enter the text / number / value which the code is required to represent. The copy button copies the image so it can be pasted into another document or image.
Once the image is on screen, in a document, or printed out, it can then be scanned by anything which can scan and decode it, such as a mobile phone app, or a barcode scanner.
As to why it's there ... I am afraid that's something I have forgotten.