Adobe Presenter is a Windows only plug-in to PowerPoint, which allows you to add audio, video, and Flash content to PPT slide decks. It also has the ability to add quiz and interactive content. Then it publishes the presentation out as a Flash (SWF) or HTML presentation, or both, which can be placed on a web server, LMS, Adobe Connect, etc. and delivered online.
Adobe Presenter Video Express is a tool for both Windows and Mac OS's that does a simultaneous capture of your screen and webcam and allows you to edit together the capture as just your webcam, just your screen or a combination of both. You can also edit in other video assets. Then it publishes out an MP4 that can be distributed through whatever means you see fit.
Does that help clarify?