There is no doubt that, so far, cookies are an indispensable web building block. Disabling them, would make it impossible to log into websites, while erasing them regularly, would probably make life more difficult than secure.
What are cookies?
Cookies are small bits of information, in the form of plain text, stored on our computer when visiting various websites.
Information stored as cookies depends on each web page. Cookie text may include our user ID, session ID, last visit date and personal preferences for a specific page.
Storing our personal preferences is the most useful job cookies do. When, for example, we choose for Facebook to remember that we have logged in, this is done through cookies. The same applies to pages that allow us to choose a different look.
Without cookies, our personal preferences would be impossible to store, and every time we enter websites, it would be as if it were our first time.
Each page can store multiple cookies on our computer, and the more we use our browser, the more the number of cookies (up to hundreds and thousands) may be stored at any time.
How cookies work…
The computer manages cookies exclusively through the browser. In fact, each browser has its own set of cookies. That’s why if we have logged into Facebook via Chrome and try to re-log via Firefox, Facebook will ask again for username and password.
A key point for cookies is that each website is allowed to control exclusively the cookies it created on our computer. That is why Facebook cannot read Gmail cookies and access Gmail’s session (and consequently our messages and contacts) without our permission.
Useful cookie implementations
As we’ve already said, cookies are necessary in order to store any personal preference on the Internet:
– The cookies allow us access to our webmail or Facebook account, or a forum, without having to enter each time username and password.
– Cookies allow us to choose themes or other display preferences on pages that allow this (e.g. Gmail) and see our settings each time we log in.
– Cookies help webpages show us content of personal interest. For example, when browsing movies, thanks to cookies, we know which pages we’ve already seen, and get suggestions relative to our interest.
All modern browsers enable us to manage cookies, and to erase last-hour, last-day, last-week or all cookie history.
Though, deleting all cookies will lose us those we might want to keep, such as the ones storing our account information for various websites.
A power-user way to manage cookies is using the popular Ccleaner application.