Windows DNS explanation

Solution 1:

Reload: re-read the zone data stored locally on the server.
Transfer from Master: update the zone data with changes from the master server.
Transfer new copy: transfer a full copy of the zone data from the master server (not only the changes).

All of this only makes sense for standard master/slave zones; Active-Directory-integrated ones don't use a master/slave model and replication is managed by AD itself.