There are multiple ways to duplicate content within Photoshop. There are, for example, multiple copy and paste features available from both the Edit menu and via corresponding keyboard shortcuts. One of the fastest ways of duplicating content is using the Move Tool in combination with the Option/Alt key to drag out a copy of something.
0:00 – Review of auto-select feature of Move tool in Photoshop
1:07 – Drag out a copy of anything in Photoshop with the mouse
Hold down the alt/option key while dragging an element with the Move tool.
While doing this, if the auto-select option is not active, ensure the layer that is to be duplicated is selected within the Layers panel.