What does the word 'public' mean in relation to class methods? How do 'public', 'protected', and 'private' differ?

The keyword public in the context of class methods means that this method is accessible from anywhere in the program, i.e., it can be called from other classes and packages.

Differences between public, protected, and private:

• public: the method or field is accessible everywhere.
• protected: accessible within the class, its subclasses, and classes in the same package (in languages like Java).
• private: accessible only within the class where it is declared.

Example in Java:

public class Example {
    public void publicMethod() { }
    protected void protectedMethod() { }
    private void privateMethod() { }
}

Here, publicMethod can be called from any class, protectedMethod — only from subclasses or within the package, and privateMethod — only within the Example class.