un tar and ownership of the extracted files

If the user extracting is a “ordinary” user, the files will be owned by that user (by default).
If the user extracting is a super user, then the files ownership will be preserved (by default).

Note: This is by default and can be overridden when needed:

From the manual page of tar:

       try extracting files with the same ownership as exists in the archive (default for superuser)
       extract files as yourself (default for ordinary users)

tar extracting to a target directory

By default untaring will put the contents into the current directory.
Sometimes it is not desirable to change directory to the target (such as in a scrip).

tar -xvvf /source/tarfile.tar -C /target

This will extract(x), very verbosly(vv) the file(f) /source/tarfile.tar to the directory(-C) /target (it will change the output folder to /target (so make sure it exists).