The first one is a typical desktop activity recorder – you mark capture area and that’s all. No fancy options: just a pure video stream from your screen. Video has very good quality (theora and vorbis codecs).
Wink is a screencaster oriented towards preparing interactive tutorials and presentations. You can record screen activity, but also pause the video, add text boxes with explanations, buttons waiting for user interaction (for example “Next” buttons). Output formats are: SWF, standalone EXE (for Windows machines only), PDF, PostScript and HTML. No typical video files, which on the other hand is not really a problem, as the framerate of the recording is pretty small. Another issue is that it apparently cannot record properly windows rendered with OpenGL (like molecular viewers) – window’s interior comes black. Even with these limitations I think Wink is better for preparing tutorials (for example on usage of some online bioinformatics service) than typical screencasting software.