A QR code is text, just like a bar code. For example it may be the text of a URL to a web page with information about a product. You scan the QR code with your smartphone and software on the phone recognizes it as a URL and opens that page in the browser.
To create one, you will need to find a suitable ActiveX control (use your favorite search engine), and put it on a form. Then follow the documentation. Perhaps you need to set the Value property of the control and it will paint the corresponding code.