Browse and Open Document buttons
These are 2 buttons that work hand in hand although they can be used separately.
They are typically used to associate a document to a record (contact, company, group, oportunity) without actually attaching it to the record. Clicking the Open button is then a lot faster that opening the documents tab and looking for a document among many others. It can also be used to open a directory.
See this video on how to set them up.
The Browse button allows the user to select a file or folder and store the path in a field.
The button has a Default Folder property. When you set it to a folder, the Open dialog box which pops up when you click the button will default to that folder so that you don't have to navigate to the same folder every time.
Open Document button
The Open Document button opens the file or folder which path is stored in the field you associate it with. Typically
the Browse and Open Document buttons are associated with the same field. One stores the path in the field, the other reads the path and opens the
file, document or folder.