How does using interfaces in PHP help in decoupling the availability of methods from their actual implementation in classes?

Using interfaces in PHP helps in decoupling the availability of methods from their actual implementation in classes by defining a contract that specifies which methods a class must implement without detailing how they are implemented. This allows for greater flexibility and modularity in the codebase, as different classes can implement the same interface in their own unique way.

interface LoggerInterface {
    public function log($message);
}

class FileLogger implements LoggerInterface {
    public function log($message) {
        // Implementation for logging to a file
    }
}

class DatabaseLogger implements LoggerInterface {
    public function log($message) {
        // Implementation for logging to a database
    }
}