Information about cookies
A cookie, what is it?
Internet, a conversation of amnesiacs!
The Internet is based on a communication protocol between machines. Thus, when you connect to a website using your computer or smartphone, your browser software (Firefox, Chrome, Safari, Microsoft Edge, etc.) sends a request to the server hosting this site and located somewhere share on the global network. If this is found, it then returns the requested information to your software, most often a web page made up of text, images or videos.
When you click on a link included on this page, your browser sends a request to the same server which returns the expected response, as long as your session on the site lasts.
As sophisticated as this principle of exchanging requests and responses may seem, communications between your machine and the server are based on a so-called “stateless” protocol. Clearly, when your browser sends a request to a server, the latter knows nothing of the previous requests that you may have sent to it previously, even very recently. In fact, the server considers each request completely independently, without keeping any trace of its previous responses.
This “stateless” communication is perfectly sufficient for the consultation of simple sites, but certain sites – such as e-commerce sites, for example – require keeping track of the actions carried out by the Internet user. Indeed, how could such a site function if the contents of your basket evaporated with each change of page? 😉
A cookie is a small data file placed on your machine by a website when you access it. This file is then automatically sent back to the site on each subsequent request, allowing the server to retrieve information on what was previously exchanged between your machine and itself. Thus, when you identify yourself on a website, it may be designed to save your first and last name in the cookie that it sends back to your browser. Since the cookie is then sent back to the server with each new request, the site can, for example, retrieve this information and display your name at the top of the web page it sends back to you.
Today, most sites, like ours, do not store “unencrypted” data in their cookies, but session identifiers in the form of a long sequence of numbers and letters. These session identifiers allow the site to uniquely identify your active session; in this way, when it receives a request with a given identifier, a site consults its register of sessions and knows, for example, that you have already identified yourself on the site and have three articles in your basket.
First, remember that a cookie is a file made up of text only; it is therefore not an executable file, nor even less a virus or malicious code. In addition, your browser ensures that a given cookie can only be read or modified by the site that created it. In addition, the site can also decide to set an expiry date for its cookies; in this case, after this date, the cookie will no longer be valid and its content ignored. If the cookie does not have an expiry date entered, then it will automatically disappear when you close your browser.
If they do not therefore constitute a threat to the integrity of your machine, cookies can nevertheless be like real little “snitches” if used in an “intensive” way. Indeed, through sessions, a site is quite capable of determining which pages you have visited, and how often. These data are generally used for purely statistical purposes in order to improve the content of the site: which pages seem to appeal to customers? Which pages, on the contrary, need to be improved?
However, some sites, usually portals or search engines, use this session data to analyze your browsing and thus be able to offer you “targeted” advertising in relation to the pages you have previously visited; who has never been “surprised” to find in the middle of a web page an advertisement for a product about which he had researched in the previous days?
Deletion of cookies
As we have seen, some cookies disappear by themselves from your machine, either because they have no expiry date specified, or because it has passed. Nevertheless, it is quite possible for you to manually delete cookies from your machine at any time and as often as you wish, via the security settings of your browser:
For example, if you are using the Chrome browser, go to the system menu then “Settings” then “Advanced settings”. Then click on “Content settings” then “Cookies”. At this stage, you can deactivate the authorization for the sites to deposit cookies on your machine, but certain sites will not be able to function any more from then on. You can also delete all cookies installed on your machine or only those linked to one or more specific sites.
All other browsers (Firefox, Microsoft Edge, Safari, etc.) offer the same functionality for controlling your cookies.
Cookies are small files placed on your machine when you browse different sites. These files are absolutely necessary for the proper functioning of most of these and do not pose any physical threat to your system. Nevertheless, the use of these without your consent may lead to the analysis and use of your browsing data for marketing purposes.