Corporate Design Manual
This is where everything that has been developed comes together and builds a guideline for the company to output content in a way that supports their own brand. It explains how and how not to use the elements of the corporate design. In one way it just sums up the corporate design and makes it graspable but as the name implies it is a manual or guideline and has to be seen like one. So whenever there is something new created, concerning the company, which has any kind of visual appearance it has to follow those guidelines and when it's not it may be unwise to use it.
This is also the final delivery of a corporate design. When a corporate design manual is handed over to the company the corporate design is finished.
Pattern Library
A pattern library is often seen as the modern version of a corporate design manual. It is a website containing all the components the company needs for visual representation. But pattern library differentiates from a corporate design manual in a big way. It is not much of a guideline. For small companies that may be fine, but for big cooperations with many people working on tasks that require a visual component, a traditional manual would serve best.