Finder windows open in one of four different views: Icon, List, Column and Cover Flow.
To change between views, click the View buttons in the toolbar at the top of the Finder window or click View and select one of the four options.
Cover Flow is useful for previewing files within a folder, as it shows a small preview of a file’s contents as you scroll through a folder.
For a larger preview, click and drag the corner of the Finder window.
If you’re a recent Mac convert coming from using Windows, there’s a familiar view you can try. Click View > Show Path Bar to display a Windows-style path of folders and sub-folders in Finder. This may make it easier to locate specific files and folders.