Intag White papers
Programming Corner
Number: 009
Date: 08 01 2002
Author: Intag
Source: Intag


A cookie is a small text file hosted in your PC by a Web server. It's useful as an administrative tool for the sender server, that it's the only capable to read it besides. Cookies cannot neither be executed nor to carry virus.

Important: A server can not access neither your name nor your e-mail address via cookies!.

Its purpose is to report server that you are again visiting a page hosted in it. If you are not allergic to cookies they are useful things even for you as a user in order to be "remembered" by Websites and allowing them to offer you some valuable services. All is a matter of common sense and the proper use of the netiquette. For instance if you register for a specific service, second time you will only need the basic login because the server will know the rest of your registration data.

If on the contrary you do not like cookies, and you heat others spying your navigation habits, you may set you browser to disable cookies but take into consideration that some sites keep relevant information hidden for people that reject cookies. You may see cookies stored in your PC, but you will only see letters and numbers identifying you, the cookie owner site address and other numbers, among them the date of loading.

Many cookies are ephemeral, lasting till for instance you put your computer off but some other are destined to live longer. These types of cookies are used to know something about your navigation habits, for instance where from you are and what pages you visit more.

When a browser requests a page, It send you back a cookie together with the requisition. In this way the server may use a cookie to identify your shopping cart. Here faces two possibilities: the first cookie, when you entered to the site, the cookie identifies as with a tag, all your shopping, and accordingly, all the items you acquire; another option is based on products: each product send a cookie to you as a potential buyer.

What type of information could the cookie obtain from you?

When you intent to access a page the server receives your IP address, the type of browser you are using and the Operating System of your computer, and that information is stored in a log file. That information is complex and difficult to handle and most times the IP does not identify the user but a network or an ISP provider with thousand of user connected at the same time or a corporate firewall.

Cookies and Customized Pages (My Page)

One cookie is sent to your computer for each item you want to see in your personalized site. When you visit the site again to look for your pages, your stored cookies are sent back to the server and in that way the server is ready to set your pages. Without cookies, the server should have to request your full information each time you want to see your personal site. In that way, the server always has your setting.

Cookies and the user habits

This is one of the most questionable uses. Within a domain cookies could be used to know what pages you visit more. By the way, no mysteries, all the information cookies provide are available via server logs!. The cookies role is to facilitate the task.

Cookies and Advertising Agencies

An advertising agency could easily know how an ad exposure behaves in different Websites, technically shifting the users-Website route. For that, when the ad appear in the user screen, the entity sending cookies would be the agency instead of the Website where the ad is hosted and form that agency server, cookies should spread to all Websites where the ad is exposed to compare the advertising efficiency of each one.

Where the persistent cookies are located?

Netscape store them as cookies text in PC's and as magic cookie in Mac's being both in the Netscape directory. Internet Explorer store them in separate files named as follows:

Where the suffix is the domain sending the cookie and at the same time these files are in the /Windows/cookies directory or in the /Windows/profiles/ users' login if the Operating System is Windows NT.

Cookie example

These files could be open to see their origin and content. Let's see one example in Windows Explorer: orvis@java file.


Orvis was the user's name and java the last part of the domain; "Counter_Cookie" is the cookie name and 7 its "value". The URL is the attribute of the domain.

This cookie has being designed to count how many times you have visited a determined page. Each time you make a visit, the cookie is sent back and the server "knows" that you have made 7 visits before and accordingly this is your eight visit, adding then one to 7 resulting a new value of 8. .

Cookies information resources

If you want more information about how to manage cookies we recommend to go to:

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