QR codes are the two dimensional bar code that appear on the ' Send' and ' Request' screens. With these you can:
Make it easy for someone else to send you dogecoin. On the ' Request' screen select a receiving address and add a label and the amount of dogecoin you want to be paid. This creates a QR code in the panel on the right. Copy it with the ' Copy' button or drag and drop it into, say, an email message and send it to the payer.
If you have a QR code, you can drag and drop it onto an existing QR code or the 'Drag QR code here' text on the ' Send' screen. It is then read and the send form is automatically populated. You can then press the ' Send' button as normal to send the payment
You can copy a QR code into your clipboard and use the ' Paste' button on the right hand side of the ' Send' screen to paste it in.
You can also drag the QR code directly to your desktop and a PNG image file of the QR code is created.
Some sites, notably Dogechain.info, provide QR codes of their dogecoin addresses. You can drag and drop these onto the target in the ' Send' screen and it will automatically create an entry in your list of sending addresses