Cookies are small files stored in your browser cache that can do many useful things have also been scrutinized for potentially compromising user privacy. So how exactly do these things work and why are they even called cookies? The name comes from ‘Magic Cookie’ which was an early term for a small piece of data passed between computers usually for identification purposes. Modern browser cookies also identify your computer but they serve the additional purpose of tracking your activity which isn’t always as nefarious as it sounds.

The way it works is that when you visit a cookie-enabled site for the first time, let’s say Amazon, the site will put a cookie on your browser that contains a unique ID. Amazon uses this ID to keep track of your session so the site knows, which shopping cart is yours and what you’ve looked at so it can suggest products based on your past activity.

Session management with cookies has many more applications though than just virtual shopping carts. The identifier in a cookie can allow a server to,

• Keep track of your login, so you don’t have to keep entering your password every time you visit a site.
• It can remember how you’ve customized the layout or appearance of a page previously.
• Cookies also allow sites to figure out how many unique visitors they get since each unique visitor has their ID contained within a cookie which is important for webmasters who need analytics data for business development.

Cookies make things more convenient but you might also hear they can also spy on you. One of the most common ways that your browser can compromise your privacy is by allowing third-party cookies that are sent from sites other than the one that you’re visiting, for instance, banner ads are often hosted on a different domain than the one that you’re actually browsing and can plant cookies on your browser that track you across multiple sites which many people find intrusive and downright creepy.

But even worse is the potential for cookie theft which is usually supersensitive things like website passwords aren’t stored in cookies but the identifier in the cookie can be used to essentially steal a logged-in session, meaning that an attacker could access your shopping cart, bank account or even medical records without even knowing your password and get this browser usually just store your cookies in plain text without any encryption making them a vulnerable target, though using websites that transmit cookie data over a secure connection can help somewhat.

So, what can you do then to mitigate these privacy risks?

• Most browsers will allow you to disable third-party cookies with a simple option, so you’ll only get cookies directly from the site that you’re visiting and if you want to take it a step further you can disable cookies entirely if you don’t mind the features that they offer.
• If you’ve got cookies on or even just in general be careful about what you click on and what sites you’re browsing. If you’re only navigating to trusted sites that are going to not spy on you then no one will be spying on you. Although it’s not always easy to tell who to trust these days.
• Periodically clearing your browser cookies and cache not only improves the security but also fixes certain problems, like loading or formatting issues on sites.
• Finally keeping the hard drive on your laptop encrypted is a pretty key one because if someone walks off with your entire computer and all the cookies on it, it’s an easy way to have the bad guys stealing all your cookies.

Here is the article shows how to clear your browser cookies.