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Cookies are messages that web servers pass to our web browser when we visit websites. Our browser stores each message in a small file. When we request another page from the server, our browser sends the cookie back to the server. These files typically contain information about us such as our name and interests.

Examples:-

Cookies are used for online shopping. Online stores use cookies that record any personal information that we enter so that we don't need to re-enter this information when we visit the website. It keeps a track of the items we add to our electronics cart as well & shows us similar advertisments.


Servers can use cookies to provide personalized web pages according to our selected preferences. The server places the information in a cookie. When we return next time, the server uses the information in the cookie to create a customized page for us.

History of Cookies

The man responsible for cookies is Lou Montulli. He developed one of the earliest Web browsers, Lynx, in 1991 and joined Mosaic Communications Corporation, later to become Netscape, in 1994. He was responsible for a variety of Web innovations such as the blink tag, server push and client pull, HTTP proxying, and cookies
Montulli had the idea to use a similar system in the Netscape browser for Web communications, and he used the familiar programming term, cookie. They were first used to verify whether users had visited the Netscape website before, and they enabled websites to remember our preferences. The cookies also presented a handy solution for virtual shopping carts, enabling e-commerce websites to remember what we were shopping for the last time we visited.
The public didn’t really become aware of them until 1996, when the media started reporting on the potential threat to privacy. Concerns focused on the fact that cookies were storing information on user’s computers without their knowledge or consent.
Types of Cookies

  • Session cookie: Also known as a transient cookie, its a cookie that is erased when we close our web browser. The session cookie is stored in the temporary memory and is not retained after the browser is closed. Session cookies do not collect information from our computer. They typically store information in the form of a session identification that does not personally identify the user.
  • Persistent cookie: Also known as a permanent cookie or a stored cookie, its a cookie that is stored on our hard drive until it expires (persistent cookies are set with expiration dates) or until we delete the cookie. Persistent cookies are used to collect identifying information about the user, such as Web surfing behavior or user preferences for a specific Web site.

Data Collection Using Cookies

A cookie collects the following information:-

  • Name - Its the file name of the cookie.
  • Host - Its the domain it is hosted on or served from.
  • Raw Host - Its the same as above but with an initial dot removed.
  • Url Domain - Its the domain in browser address bar at the time the cookie is downloaded.
  • Path - Its the location in the host domain where the cookie is set.
  • Is Secure - Its set if it is an https only cookie.
  • IsHttpOnly - Its set if the cookie can only be accessed by http, a level of security which prevents cross server scripting attacks.
  • IsSession - Its set if the cookie is session only.
  • Expires - Its the date when a persistent cookie is set to be deleted.
  • IsNew - It identifies whether a persistent cookie of the same name and host is already on the machine or not.
  • SessionId - It uniquely identifies a browser session. It is generated by the database and enables generation of statistics around the number of cookies set in a single browser session.
  • TimeStamp - The time stamp of each database record as it is created.
  • BrowserId - Its a code that identifies the type of browser (e.g. Firefox, Chrome). This is necessary because not all browsers enable collection of the same data. 

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