WHAT ARE COOKIES? WHAT IS A COOKIE?
Cookies are small files that are stored on a user’s computer. They are designed to hold a modest amount of customer-specific data and the website and can be accessed by either the web server or the client computer. This allows the server to deliver a page tailored to a specific user, or the page itself may contain a script that is aware of the cookie data and thus can carry information from a visit to the next website (or website).
ARE COOKIES ACTIVATED IN MY BROWSER?
To check if your browser is configured to allow cookies, visit the Cookie checker. This page will attempt to create a cookie and report whether or not it succeeded.
For information on how to enable or disable cookies, see “Enabling cookies”.
For information on how to delete and delete cookies, see “Deleting cookies”.
Can I view the cookies I have on my computer?
Most browsers have a configuration screen that allows the user to see what cookies have been stored on the computer and optionally delete them. For more information, see the cookie preview page.
Please note that it is not possible for a webpage to view cookies set by other sites, as these would be a privacy and security issue.
WHAT IS IN A COOKIE?
Each cookie is effectively a small search table that contains pairs of values (key, data) – for example (first name, John) (first name, Smith). After the cookie has been read by the code on the server or client computer, the data can be retrieved and used to properly customize the web page.
When are cookies created?
Writing data to a cookie is usually done when a new web page is loaded – for example after pressing a “Send” button, the data management page would be responsible for storing the values in a cookie. If the user has chosen to disable cookies, then the write operation will not succeed, and subsequent sites that rely on the cookie will have to take a default action or ask the user to re-enter the information that was stored in the cookie.
WHY ARE COOKIES USED?
If there is a large amount of information to store, then a cookie can simply be used as a means of identifying a given user so that additional related information can be searched on a server-side database. For example, the first time a user visits a site, they can choose a username that is stored in the cookie and then provide data such as password, name, address, preferred font size, page layout, etc. – this information would all be stored in the database using the username as the key. Later, when the site is reviewed, the server will read the cookie to find the username, and then retrieve all the user information from the database without re-entering it.
HOW LONG DOES A COOKIE TAKE?
The expiration time of a cookie can be set when the cookie is created. By default, the cookie is destroyed when the current browser window is closed, but an arbitrary period may persist after that.
WHO CAN ACCESS COOKIES?
When a cookie is created, it is possible to control its visibility by setting the “root domain”. It will then be accessible to any URL belonging to that root. For example, the root could be set to “whatarecookies.com” and the cookie would then be available for the sites “www.whatarecookies.com” or “xyz.whatarecookies.com” or “whatarecookies.com”. This can be used to allow related pages to “communicate” with each other. It is not possible to set the root domain to “higher level” domains, such as “.com” or “.co.uk”, as this would allow wide access to the cookie.
By default, cookies are visible to all paths in their domain, but at the time of creation they may be restricted to a particular subpath – for example, “www.whatarecookies.com/images”.
HOW SAFE ARE COOKIES?
There are many concerns about privacy and security on the Internet. Cookies are not, in and of themselves, a threat to privacy, as they can only be used to store information that the user has voluntarily provided or already has with the webserver. While this information may be made available to certain third-party websites, it is no worse than storing it in a central database. If you are concerned that the information you provide to a web server will not be considered confidential, then you should ask yourself whether you actually need to provide this information.
WHAT ARE THE TRACKING COOKIES?
Some commercial sites include embedded advertising materials that are provided from a third-party site, and such ads may store a cookie for that third-party site, containing information that is provided to them from the site that contains – such information may include the name of the site, certain products viewed, pages visited, etc. When the user subsequently visits another site that contains a similar embedded ad from the same third-party site, the advertiser will be able to read the cookie and use it to determine some information about the user’s browsing history. This allows publishers to run targeted ads in the user’s interest, so in theory, they have a higher chance of being relevant to the user. However, many people see such “tracking cookies” as an invasion of privacy because they allow an advertiser to create user profiles without their consent or knowledge.