Jpeg Raw and Tiff
I will try and put it in simple terms making it easier to understand.
All pictures are initially shot in grey, and each picture produces data which a camera reads and converts to colour. Hence grey cards are used as a basic colour setting, about 18% grey is the norm for a card.
So now we have a grey image in camera and the camera grabs the simpliest way to reproduce colours (Jpeg) This allows a limited amount of editing
Now RAW and Tiff dig a little deeper into that data and discovers there is a lot more to be extracted out of that greyness. That then allows more editing control available hence a better photograph.
I tend to think of it like this
You look at a single sheet of glass showing an image (Jpeg) and that is it
But
Underneath that top sheet of glass are others each with its own colour . Raw and Tiff see those other sheets of glass and adds them together making up the whole photo.
So if one
wants to edit a photo there is a lot more data
(sheets of glass) the editing program can grab to correct a photo( RAW or TIFF).
The problem is posting in a forum or most other places is because so much data has been extracted In RAW or TIFF it is too much for sending to third parties, but great for hard copy prints
Therefore to make it easier to post they have to be converted back to Jpeg from RAW or Tiff. That then reduces the data but still keeps the contents extracted from Raw or Tiff file
Don't know if that makes sense but only way I know of explaination.