Stores data on the client's machine for tracking or preferences.

Use mysqli_query() and mysqli_fetch_assoc() for result handling.

PHP is a server-side scripting language designed for dynamic web page development.

Stores user data across multiple pages until the session ends.

Start with $, followed by the variable name: $name = "John";.

String, Integer, Float, Boolean, Array, Object, NULL, Resource.

PHP stands for "PHP: Hypertext Preprocessor".

echo is faster; print returns a value (1), allowing use in expressions.

== checks value, === checks value and type.

Includes a file but stops script if the file is missing.

A variable that holds multiple values in a single name.

Use echo or print to output text or variables.

Checks if a variable is empty or not.

Indexed, Associative, and Multidimensional arrays.

$person = ["name" => "John", "age" => 30];

Use mysqli_connect() or PDO for database connections.

Includes and evaluates a file; continues script if file not found.

Call session_start(); at the beginning of the script.

Use //, # for single-line, or /* */ for multi-line comments.

Checks if a variable is set and not NULL.

Use $_GET or $_POST superglobals to collect submitted form data.

Use header("Location: page.php"); followed by exit;.

A superglobal that contains server and execution environment information.

function sayHello() { echo "Hello"; }

Use $_FILES, move_uploaded_file() to process uploaded files.