You can combine selections made with the marquee tools, the lasso tools, the Magic Wand tool, and/or the Quick Selection tool. Each of these tools has options for combining selections in its Options bar.

To add to a selection, click the Add to selection icon in the Options bar, or press the Shift key on the keyboard as you make another selection.

To subtract from a selection, click the Subtract from selection icon in the Options bar, or press the Option key (MacOS) or Alt key (Windows) as you select an area you want to remove from the selection.

To create an intersecting selection, click the Intersect with selection in the Options bar, or press the Option + Shift keys (MacOS) or Alt + Shift keys (Windows) as you select an intersecting area.