Electoral Divisions (ED) were created with the poor law unions for election of guardians and levying of rates according the expense of each division.

With the creation of Rural Districts and Urban Districts under the 1898 Local Government Act, electoral divisions were renamed District Electoral Divisions (DED). Hence this is the title in the censuses of 1901 and 1911.

If we had the censuses of 1891, 81, 71 etc, you would see the areas listed as EDs.

They have nothing to do with baronies, which incidentally were abolished under the Act of 1898.