A cookie is a harmless text file that is saved in your browser when you visit virtually any web site. The purpose of a cookie is for the website to be able to remember your preferences regarding it the next time you visit it. In a nutshell, cookies customize your web experience. Although many people may not know it, cookies have been being used for 20 years, when the first World Wide Web browsers appeared.
A cookie is not a virus, neither is it a trojan, or a worm, nor spam, or spyware, and it does not generate pop-up windows.
Cookies do not store sensitive information about the website user, such as credit card or bank account data, photographs, ID or social security number, personal information, etc. The data saved by these is exclusively one of technical character, such as the site’s display preferences, content personalization, etc.
The server does not relate to you as a person but to your web browser. In fact, if you regularly browse through Internet Explorer, for instance, and then try to enter the same site through a different browser, like Firefox or Google Chrome, you will realize that the site will not be able to identify you as user with your saved preferences. That is because the site had its cookies saved in the browser that you regularly used, but not in the new one.
First-party cookies are those generated by the website you are visiting, whereas third party cookies are generated by external service providers such as Facebook, Twitter, Google, etc.
In order for you to understand the full extent of the effect that turning off cookies can have, we provide here some concrete examples of what happens when you do it:
Yes, cookies can not only be deleted but also blocked in general or in particular for a specific domain.
To delete a website’s cookies you must go to your browser’s configuration and from there search the cookies related to the domain in question and proceed to erase them.
Most browsers allow you to refuse to accept cookies and to delete cookies. The methods for doing so vary from browser to browser, and from version to version. You can however obtain up-to-date information about blocking and deleting cookies via these links:
(a) https://support.google.com/chrome/answer/95647?hl=en (Chrome);
(d) https://support.microsoft.com/en-gb/help/17442/windows-internet-explorer-delete-manage-cookies (Internet Explorer);
(e) https://support.apple.com/kb/PH21411 (Safari); and
Blocking all cookies will have a negative impact upon the usability of many websites.