Circles are another way to use your Dropzone destinations.
To activate Circles, move your mouse to the middle of the far right of your screen. Then click on the half circle that appears.
You can also activate Circles by dragging files or folders to the far right of the screen. Once the circles open, you can drag the files onto the destination you want to use.
In the Dropzone preferences you can choose which destinations show in Circles by ticking and unticking the checkboxes in the Circle column. You can choose up to 5 destinations to show in Circles.
In the Dropzone preferences under the Settings tab you can toggle the location of Circles between the left and right of your screen.