What is the difference between Aurora Mysql 5.7.x and Aurora 2.x.x

I have an RDS instance with Aurora Mysql 5.7.12 and I noticed that there are other versions of Aurora Mysql 5.7, but I don't understand what is the difference between them. Some of the version listed are: - Aurora (MySQL)-5.7.12 <- The one that I have. - Aurora (MySQL 5.7)-2.03.2 - Aurora (MySQL 5.7)-2.03.3 - Aurora (MySQL 5.7)-2.03.4 - Aurora (MySQL 5.7)-2.04.1 - Etc... I attach an image of the AWS Console: I want to chose the right version (the one that have most bug fixes in order to have better stability in my system).