14 January 2012

All About Cookies

Anyone who is using the Internet has heard this word Cookie. But do you know what cookies exactly are? Are they harmful for your system? Where cookies stored on your PC? How to find out what kind of cookies a specific site stored in your system? These are the question that I will try to answer in this article.

What is a cookie?

A Cookie is also known as HTTP Cookie, Web Cookie or Browser Cookie is a text file that a Web server stores on the user’s hard disk. With cookies, websites are able to save information like user preference, site visited, etc. on his/her machine. Cookies are small text files, and created when a user use Internet browser to visit a website. The jobs of cookies are to keep track of user activities, their registered login, preference and other actions. We can say a cookie stored on your system by the server on the client side of a client/server communication.

How they work?

When you visit a specific website, your browser stores the message sending by the Web server as a text file. So in that way the server can ask for retrieving the message when it wanted or need it. Let me give you an example, when you enter a Web site that offers you products to buy, you may add some products to shopping cart and exit from the site. Next time you return the site you will see your products are still in the cart. Because the website uses cookies to remember your shopping order.

As I said cookies are text files that given your system an ID tag. The information is stored as name-value pairs. They can be read only by the website that created them. A name-value pair or field-value pair is a technique in data representation in computer science. In this way programmers are able to extend the original code without modifying existing code or data. Some other applications that use a name-value pair for representing data are E-mail and Network Protocol.

The website stores a text file with ID tag for a specific action like your registered login on your hard disk so you don’t need to enter your user ID and password each time you enter the site. This text file or cookies does not contain many information but usually they include the URL of the website (the one that created them), and a random number.


Cookies categorized in

Session cookie
Persistent cookie
Secure cookie
HttpOnly cookie
Third-party cookie
Super cookie
Zombie cookie

Among these cookies Session and Persistent are the most important cookies, so let explain about them.

Session cookie

This cookie also known as Transient cookie and it is deleted or erased when the user exit from the browser. Session cookies are stored in RAM and not retained after the browser is closed. They do not collect information from your system and instead they save information as session identification. They created when no Expires directive is provided in their time of creation. The Expire directive tell the internet browser when it has to delete the Session cookie.

Persistent cookie

Persistent cookie or Permanent cookie, is a cookie that will be stored on user hard disk till its expire date or user himself delete it manually. Unlike the Session cookie, this cookie collects identifying information about the user that is why it is also called tracking cookie. These cookies used for record user activities such as user preference.

Where they are stored?

It depends on your operating system. For Windows XP, they are located in the

%USERPROFILE%\Application Data

And for Windows Vista or 7, you can find them in


Select Run and type %APPDATA% to go to Application Data folder. Remember if you want to see the Cookies folder in the Windows directory, first you must unselect Hide protected operating system files (Recommended) in the View tab of Folder Options.

But the easiest way to find them in your system is to write cookies in the search bar of Windows and hit the Enter. You should know also each browser stores cookies in different locations.

Are they harmful to our PC?

A cookie cannot be used to disclose your identity or personal information because they contain little amount of information. Also it cannot carry viruses or install any malware. But these days because of increasing of competition in global marketing, it can be used by a spyware to check the user Internet surfing activities and habits. Also social networking websites like Facebook track their users by cookies.

Read more about how Facebook tracks its users here.

How to find out what kind of cookies a particular site store in your system?

The best and easiest way is to search the word cookies in Windows operating system, but I am going to show you a trick to see what kind of cookies a web site stores on your PC. First of all the Fire Fox must be installed in your system.

1. Go to Fire Fox and open your desired website (for example Facebook).

2. Left-click on favicon icon on the left side of Fire Fox address bar.

3. Select More Information and click on View Cookies.

4. Now you are able to see the related cookies about the currently opened website. In the Cookies window you are also able to Remove a single cookie or Remove all cookies.

For final words I can say that Cookies can help websites to be more efficient and they let users to store preference, user names, register products and services and customize pages so they give them more of content they like and less of the content they don’t.