HTTP cookie

HTTP cookie

An HTTP cookie (also called web cookie, Internet cookie, or simply cookie) is a small piece of data sent from a website and stored on the user's computer by the user's web browser while the user is browsing. Cookies were designed to be a reliable mechanism for websites to remember stateful information (such as items added in the shopping cart in an online store) or to record the user's browsing activity (including clicking particular buttons, logging in, or recording which pages were visited in the past). They can also be used to remember arbitrary pieces of information that the user previously entered into form fields such as names, addresses, passwords, and credit card numbers.

Functionality

Cookies perform essential functions in the modern web. For example, they are used to maintain a "session" between the web server and the client's browser, making it possible for the user to visit different parts of a website without having to log in again. This session management is a critical component of web security and user experience.

Types of Cookies

There are several types of cookies, each serving different purposes. These include:

• Session cookies: Also known as in-memory cookies or transient cookies, these are erased when the user closes the browser. They do not collect information from the user's computer but typically store information in the form of a session identification that does not personally identify the user.
• Persistent cookies: Also known as permanent or stored cookies, these are stored on the user's hard drive until they expire (persistent cookies are set with expiration dates) or until the user deletes the cookie. Persistent cookies are used to collect identifying information about the user, such as web surfing behavior or user preferences for a specific website.
• Secure cookies: These are used to encrypt information to keep the data safe, especially in transactions over the HTTPS protocol. Secure cookies can only be transmitted over an encrypted connection (i.e., HTTPS).
• Third-party cookies: These are cookies that are set by a domain other than the one being visited by the user. They are used for cross-site tracking, retargeting, and ad-serving.

Privacy Concerns

The use of cookies has raised privacy concerns because they can track a user's browsing activities. In response, various mechanisms have been developed to increase privacy protection, such as the "Do Not Track" feature and regulations like the European Union's General Data Protection Regulation (GDPR), which requires websites to obtain user consent before using cookies.

Managing Cookies

Most web browsers allow users to control cookies through the browser's settings. Users can delete cookies, prevent them from being stored, and choose to receive a notification before a cookie is stored on their device. However, disabling cookies may prevent users from using certain parts of a website or limit their functionality.

See Also

• Web storage
• Session (computer science)
• Internet privacy