Learning how to import the right way, the hard way

Copy as DNG – canon and nikon have a different ending when we shoot in RAW.  If we want to combine photos from different types of camera we use "copy as DNG"
Copy – your images will be in lightroom but you will have a copy depending in which folder you will save them.
Move –your images will move from source directory to a specified location in original file format.
Add - files will not copied or moved to a new location, instead LR will just move them to the catalog you are using.