On May 7th 2019, we migrated ABA from version 1.0 to version 2.0. Note, ABA versioning does not relate to Carbano protocol versions. ABA v2 is simply the updated token - used in Carbano protocol 3.0 and beyond.
ABA is the Carbano protocol token, used to incentivize protocol-desirable behaviour from liquidity providers, insurers, and DAO governors. Protocol fees come from Carbano L2 economic activity, and flow into productive Carbano network participants and into ABA itself. To learn more about the ABA token model, please check out our blog post.