About the differences between the package specification of `yarnpkg/berry` and `yarnpkg/yarn`. 

The released packages listed for [`yarnpkg/yarn`](https://github.com/yarnpkg/yarn/releases) is named after yarn, while the released packages for [`yarnpkg/berry`](https://github.com/orgs/yarnpkg/packages?repo_name=berry) are so many packages.

I am very confused about this. Any hints will be highly appreciated.

Regards,
HY
