How do methods differ in programming if their names start with an uppercase or lowercase letter?

In Go (Golang), the case of the first letter of a method or function name determines its visibility:

• If the name starts with an uppercase letter, the method or function is exported and accessible from other packages.
• If the name starts with a lowercase letter, the method or function is unexported and only accessible within the package.

For example:

package example

type MyStruct struct {}

func (m MyStruct) ExportedMethod() {}  // accessible from other packages
func (m MyStruct) unexportedMethod() {} // accessible only within the package example

This simple rule helps manage scope and encapsulation in Go.