They can be as similar or as different as you want them to be. You can automatically produce a professional-quality printed document. You have complete control over attributes such as paper size, margins and styles. You can use advanced features such as margin notes. There are numerous options for customizing your project for the target medium.
Text ranging from a single word to an entire chapter can appear in only one format.
You can use completely different graphics in the Help file vs. the printed document. For example, you might include screen shots in the manual, but not in the Help file. By maintaining your original in Help format, you can take advantage of the many features in HelpBreeze which are geared toward navigating in your documents, managing large projects and sharing information among multiple authors. Many authors need to create both printed and online documents for some projects, but for other projects they need only the Help file. The Document Wizard is there if you need it, but it won't get in your way if you are only interested in producing a Help file.