What are the key differences between using a function and a method within a PHP class, and how should they be implemented effectively?

When working with PHP classes, functions are standalone blocks of code that can be called within the class or outside of it, while methods are functions that are defined within a class and can only be called on instances of that class. To implement them effectively, use functions for general-purpose tasks that are not specific to a particular class, and use methods for actions that are closely related to the class's properties and behavior.

class MyClass {
    // Method
    public function myMethod() {
        // Code here
    }
}

// Function
function myFunction() {
    // Code here
}