The document window is where your images appear. You can open multiple windows to display different images or different views of the same one. A list of open windows appears in the Window menu. To bring an open image to the front, choose the file name from the bottom of the Window menu. Available memory may limit the number of windows per image.
View images in multiple windows
Displays undocked windows stacked and cascading from the upper-left to the lower right of the screen.
Displays windows edge to edge. As you close images, the open windows are resized to fill the available space.
You can use the Hand tool’s Scroll All Windows option to scroll through all open images. Select it in the options bar and drag in one image to scroll through all visible images.
Match zoom and location in multiple images
Photoshop automatically scrolls to the same relative location on the horizontal and vertical axes. You may need to manually scroll to reveal the edges of images.