In Object oriented programming, we are used to public, private, protected type of access mechanism. Go is different. Everything in Go is about package.
Package is a self-contained unit of code. Every folder in our source tree is a self-contained user code. We will get deeper into that in package oriented design section. For now, if we are thinking about a package being that self-containing code, firewall that separates code and having language supported for it then we can think of encapsulation being associated with the package itself.
The idea is: anything that is named in a given package can be exported or accessible through other packages or unexported or not accessible through other packages.