remote: all the clips from the same source media are adjusted at the same time (you adjust one clip and the rest get the same grade.) - this is the default operation of Resolve. new remote version: this clip can now have its own grade (remote ver 2) and new adjustments will not affect other clips from the same source media, you can apply this grade to other clips from the same source media by selecting remote ver 2 on those clips - otherwise those stay grouped with the original remote ver 1 grade. local: create a new local version if you want a new grade for that clip, and it will not be available to the rest of the clips from that same source media. batch unlink: this will "unlink" all clips so that they are independent and grades to one will not affect the other. NOTE: if you already have grades applied and choose this option all grades will be lost, so this is typically done before any grading is done to the sequence. This also means that if you reconform the edit and bring in a new xml, those grades will not be automatically applied to the new sequence. This also means that you can have multiple sequences of the same edit and grade them independently without the grades "rippling" to the other sequences. batch copy: similar to batch unlink, except that any grades that have been applied are preserved on the newly "unlinked" clips.
this can be a little confusing at first, but after using a bit it becomes very clear. If I have incorrectly described anything, please correct my explanation and I will edit.