CHG_CANON wrote:
The latter. LR "imports" a copy of the original, leaving the original safe and unchanged. LR edits are stored inside a relational database as a step-by-step history (log) against the imported copy. On-demand, those LR edits can be exported creating a new and separate output file with any number of output options / combinations covering pixel resolution, file size, colorspace, file format, w/ or w/o watermark, etc.