TTR is a digital photography technique that can be applied to both jpeg and raw photography but it is a very easy way to help extend the “apparent” dynamic range of an image when you want to stretch the tonal range in post processing, but there are some draw backs.
The theory is by ensuring the the exposure is spread across the full range of the of the camera’s sensor ability, even if the image is slightly overexposed the strength of the intensity can be pulled back to better develop the fullest possible dynamic range. The biggest risk is that the highlight get blown out (turned white) and then the detail within them can not be recovered.
In this example I have taken the +1.5 EV photo from the original bracketed set (ie the one that was deliberately over exposed) and used Aftershot Pro to lift the contrast a little, pull back the exposure and lift the vibrance a little. This has darkened the sky a just a fraction but retained the detail in the shadows in the foreground.
Once again Cambridge in Colour gives a great guide to this exposure & related strategies.