Yes, you can adjust only parts. For example, if the pic had been exposed correctly for the foreground and over exposed the sky, you can darken just the sky. Did you start with a jpeg or dng file? A jpeg is created by the camera's presets inside that edit the raw information to make a photo it thinks is right. Starting with the raw file you control what you want to do.
A dng file may be 17MB while the camera's processed jpeg may be 7MB. That's a lot of information edited out.
A dng file may be 17MB while the camera's processed jpeg may be 7MB. That's a lot of information edited out.