Blacks vs Shadows

[lluis]

Hi, I've got a question.
When I'm editing a picture in Lighroom and I want to strecht the histogram on the left side, I doubt to go up blacks vs go down shadows in the tone curve.
What is the difference in doing one thing or another? What do you use first?

Thank you.

Lluis

[NikoJorj]

I'd say that (unless you change the border of the zone in the tone curve panel?) the shadows slider has influence on a broader range of tones and therefore may more block the shadows, whereas the Blacks slider keeps better detail and opennness in the shadows.
I nearly always go first for Blacks if the need is to "sit down" the blacks, and not to darken the picture.