EXIF information--shutter speed

[camner]

My A75 reports two different EXIF values related to shutter speed/exposure time.

For example, in a given image, Exposure time is 1/500 sec while Shutter Speed Value is 1/256 sec.

A post on this forum suggests the difference is "rounding", but 1/500 and 1/256 are far too far apart for rounding error, I would think.

Does anyone have an idea what these two EXIF values represent?

[PacAce]

I wonder if it has anything to do with electronic shutter time (Exposure time) vs. the actual mechanical shutter time (Shutter Speed Value)? I wouldn't be suprised if that's why there's a discrepancy. If this were the case, the electronic shutter time would determine the actual exposure.