NEC ECC: Dispute avoidance board under NEC4

What is the difference between a dispute board and a dispute avoidance board under the NEC4 condition’s of contract?

A dispute board isn’t a term used in NEC4 contracts, Option W3 defines the term Dispute Avoidance Board at clause W3.1(1) and describes what it’s role is, how it is constituted and how it acts.