extensions vs extension: What are the differences?

Developers describe extensions as "A compiler for APIs described by the OpenAPI Specification with plugins for code generation and other API support tasks". A compiler for APIs described by the OpenAPI Specification with plugins for code generation and other API support tasks. On the other hand, extension is detailed as "The self-managing". The self-managing, auto-upgrading, Kubernetes distribution for everyone.

extensions and extension belong to "Go Modules Packages" category of the tech stack.

extensions and extension are both open source tools. It seems that extension with 7.08K GitHub stars and 4.07K forks on GitHub has more adoption than extensions with 525 GitHub stars and 66 GitHub forks.