A package in Go represents a unit of related code. Other languages often call them libraries.
A package consists of multiple files in a single directory. There's one-to-one mapping between a directory and a package.
You can have multiple packages in a single repository.
Go standard library is provided as a set of packages.
A package is identified by import path e.g.
github.com/gomarkdown/markdown is an import path of a package that parses markdown format.