The new column header controls also feature two new views that you can use to browse your content. The Stack view displays your content stacked by the values in a specific column. For example, if you select the Authors column header and choose to stack by author, all of your files currently in view will automatically be rearranged into stacks organized by the author's name.
The Stack view displays your files stacked by a specific value associated with your files, such as author name, date, application, or keyword.
These stacks behave like traditional folders, so you can click to open them and see all of the items located in that stack. Unlike traditional folders, however, stacks have no physical location on your computer. In a sense, they are virtual views of your content. More importantly, if a file has two authors (for example, a document was authored by Tim and Paul), that file is included the stacks for both Tim and Paul, providing you with the ultimate flexibility in how you find and organize your files.
The Group By view is similar to the Stack view, but it takes the content files and places them into groups according to the values of a particular column header. Grouping your files by author will give you a more granular view of which documents belong to which author.
The Group By view displays your files in groups according to the values of a particular column header.