Implementing session management and user authentication in PHP web applications Mocktest

Session management in PHP allows the server to maintain stateful information about a user's interaction with the application across multiple requests, facilitating personalized user experiences.

The session_start() function is used to start a new session or resume an existing session in PHP. It initializes the $_SESSION superglobal array for storing session data.

The $_SESSION superglobal array in PHP is used to store session data, such as user-specific information, preferences, and shopping cart contents, across multiple requests.

The session_destroy() function is used to destroy a session and delete all session data from the server in PHP. It effectively logs the user out and terminates the session.

User authentication in PHP web applications is used to verify the identity of users accessing the application, ensuring that only authorized users can access restricted resources.

Username and password authentication is a common method used for user authentication in PHP web applications. Users provide their credentials to authenticate themselves.

Hashing is used to securely store passwords by converting them into irreversible hash values, preventing plaintext passwords from being exposed in case of data breaches.

The password_hash() function is commonly used in PHP to securely hash passwords using strong hashing algorithms such as bcrypt or Argon2. It generates a cryptographically secure hash value.

Salting passwords before hashing adds a random string of characters (salt) to each password, making it unique and significantly increasing the complexity of hash calculations, thus preventing rainbow table attacks.

User authentication in PHP using a database involves querying the database to validate user credentials (e.g., username and hashed password) submitted via a login form.