Question

which tool allows the user to switch between foreground and background simuntanesously​

Answer 1

When you are working in Photoshop and you need to switch colors quickly while working you can do it with a simple key stroke.

Swap foreground and background colors

Hitting the “X” key will switch the foreground and background colors. (the “X” can be upper or lower case)

Make the foreground and background colors Black & White

If you hit the “D” key it switches Black to the foreground color and White to the background color. (the “D” can be upper or lower case)