объедините две или более историй развития вместе  (Join two or more development histories together)
  
MERGING TAG
When merging an annotated (and possibly signed) tag, Git always
       creates a merge commit even if a fast-forward merge is possible,
       and the commit message template is prepared with the tag message.
       Additionally, if the tag is signed, the signature check is
       reported as a comment in the message template. See also
       git-tag(1).
       When you want to just integrate with the work leading to the
       commit that happens to be tagged, e.g. synchronizing with an
       upstream release point, you may not want to make an unnecessary
       merge commit.
       In such a case, you can "unwrap" the tag yourself before feeding
       it to git merge, or pass --ff-only when you do not have any work
       on your own. e.g.
           git fetch origin
           git merge v1.2.3^0
           git merge --ff-only v1.2.3