Difference between restart image and receiver power up

[twol]

First apologies if in wrong section:)
So another poster had an issue where they have different results between power up and image restart .... and I am contemplating some work in that area at the moment ........
So Question: can anyone tell me the differences between power up (power switch on) and an image restart? Obviously, the latter starts from power off but the flash memory etc still retains its information, so is there any difference?

Thanks for any responses! :)

[IAmATeaf]

Logically there should be now differences between the two and if there are then I too would be interested in the what and the why :)