To retrieve data sent in the URL

To handle file uploads

To store data submitted through a form using the POST method

To store information about cookies

Contains information about the client's browser

Stores session variables

Provides information about the server and current page

Holds database connection details

POST requests can be cached, GET requests cannot

GET requests can be cached, POST requests cannot

POST requests are idempotent, GET requests are not

GET requests are idempotent, POST requests are not

To handle file uploads

To manage session data

To store server configuration information

To contain the elements of the $_GET, $_POST, and $_COOKIE arrays

$_SERVER array

$_ENV array

$_FILES array

$_REQUEST array

To resume the current session or start a new session

To end the current session and remove session data

To close a session with fresh data

To destroy all session variables

Data Type Definition

Document Type Declaration

Document Type Definition

Data Type Declaration

To define the structure and data types of XML documents

To handle user input in XML

To manage session data in XML

To store server configuration information in XML

To convert XML data into HTML

To validate and parse XML data

To create XML documents

To handle user input in XML

Version and encoding information

Document type declaration

Root element

Attributes of the root element