What are the key components of a forum structure in PHP?

// Sample PHP code for a basic forum structure

// User authentication
function authenticate_user() {
    // Code to authenticate user
}

// Create new thread
function create_thread($title, $content) {
    // Code to create a new thread with title and content
}

// Reply to thread
function reply_to_thread($thread_id, $content) {
    // Code to reply to a specific thread with content
}

// Display threads and replies
function display_threads() {
    // Code to display all threads and their replies
}

// Moderate content
function moderate_content($thread_id, $reply_id) {
    // Code to moderate content by deleting threads or replies
}