What determines the access scope of a variable declared with the private modifier?

In Go, the scope of a variable is determined by the case of its first letter, not by a private modifier as in other languages. If a variable's name starts with a lowercase letter, it is only accessible within the same package (package-private). If it starts with an uppercase letter, the variable is exported and accessible from other packages. Thus, "privacy" in Go means restricting access at the package level, not at the class or function level.