But the movement may also trigger a full command. Or, moving a circle in a drawing program changes the look of the picture being drawn. For example, moving a column divider to the right makes that table column wider. The outcome of all these steps may simply be that the object has been relocated.

Finally, the user deselects the object - for example, by letting go of the mouse button.

This is the “drag” part of the operation.

While keeping the object selected (e.g., by continuous pressure on the mouse button), the user then moves the pointing device (mouse, finger, etc.) to some desired target.

Other selection techniques are possible, but not as common - for example, speech (“select the red car”) or “grabbing” an object in a VR or AR environment.

To initiate the interaction, users acquire an object - using a mouse or touch gesture (such as a mouse click or, respectively, a long press).

(In principle, we can drag invisible objects, but usability would surely suffer.)

As with all direct-manipulation interactions, items of interest need to be visible on the screen - for example, icons, thumbnails, or explicit interface elements, such as column dividers in a table or spreadsheet.

It is a type of direct manipulation, particularly useful for grouping, reordering, moving, or resizing objects. Drag–and–drop has been around since the dawn of GUIs and is familiar to most users.

Principle app button hover state