Difference between EXIF and ExifTool info panels?

[lphilpot]

Although I'm not an exif expert, I know what it is at a high(er) level. I'm also familiar with Phil Harvey's ExifTool. But what's the difference between the two panels? Apparently when a file has no exif tags, the EXIF panel is absent, but the (somewhat populated) ExifTool panel remains. In such as case, does the ExifTool panel show only the "non-exif" info that's 'left'?

Just curious - Thanks.

[xnview]

'ExifTool' tab uses third party tool 'ExifTool'. 'EXIF' tab uses internal decoder.