Curves adjustments are one of the key tools in photo editing, and Lightroom offers three ways of making curves adjustments. What’s more, the curves tools look different in Lightroom CC and Lightroom Classic CC. Complicated? Not once it’s explained…
The parametric Tone Curve panel in Lightroom CC and Lightroom Classic CC splits the tonal range up into four sections: Shadows (the darkest), Darks, Lights and Highlights. This is slightly more precise than photographers' usual description of 'shadows', 'midtones' and 'highlights'.
If it's helpful, you could think of Adobe's 'Darks' and 'Lights' as being 'dark midtones' and 'light midtones'.