Stacks let you group files together under a single thumbnail. You can stack any type of file. For example, use stacks to organize image sequences, which often include many image files.
Adobe Bridge stacks are different from Photoshop image stacks, which convert groups of images to layers and store them in a Smart Object.
Commands that apply to a single file also apply to stacks. For example, you can label a stack just as you would a single file. Commands you apply to expanded stacks apply to all files in the stack. Commands you apply to collapsed stacks apply only to the top file in the stack (if you’ve selected only the top file in the stack) or to all files in the stack (if you’ve selected all files in the stack by clicking the stack border).
The default sort order in a stack is based on the sort order for the folder that contains the stack.
For a tutorial on stacking files, see Stacking and renaming files by Conrad Chavez.
Note: While you can add a stack to another stack, you cannot nest stacks. Files in the added stack are grouped with the existing stack files.
In stacks that contain ten or more images, you can preview (scrub) the images at a specified frame rate and enable onion skinning, which allows you to see preceding and succeeding frames as semitransparent overlays on the current frame.