https://photography.tutsplus.com/tutorials/the-complete-beginners-guide-to-shooting-high-key–photo-2949

High key is a technique that blows out any areas of deep shadow to make pictures look more beautiful, softer or more feminine and is a great form of artistic expression for the keen photographer, most often seen in fashion and beauty magazine and shots of young children or idyllic landscapes and so on.

Applying the high key effect to landscapes can also be done a tutorial for lightroom users is here.

Creating a High Key Landscape Using Lightroom in 6 Simple Steps