A cookie is a message given to a web browser by a web server. The browser stores the message in a text file. The message is then sent back to the server each time the browser requests a page from the server.
Cookies may also be called a web cookie, Internet cookie, browser cookie or HTTP cookie.
What do Web Cookies Do?
The main purpose of a cookie is to identify users and possibly prepare customized web pages for them. When you enter a website using cookies, you may be asked to fill out a form providing such information as your name and interests. This information is packaged into a cookie and sent to your browser which stores it for later use. The next time you go to the same website, your browser will send the cookie to the server. The server can use this information to present you with custom pages. For example, instead of seeing a generic welcome page you might see a page that welcomes you by name or shows when you last visited the site.
Information Obtained by Cookies
Cookies have parameters that can be passed to them:
- The name of the cookie.
- The value of the cookie.
- The expiration date of the cookie: this determines how long the cookie will remain active in your browser.
- The path the cookie is valid for. Web pages outside of that path cannot use the cookie.
The domain the cookie is valid for. This makes the cookie accessible to pages on any of the servers in a domain.
The need for a secure connection: this indicates that the cookie can only be used under a secure server condition.
UNIX Magic Cookies
The name cookie derives from UNIX objects called magic cookies. These are tokens that are attached to a user or program and change depending on the areas entered by the user or program.