What Are Browser Cookies and How Do They Work?

Anyone who has surfed the web will have come across browser cookies at some point. They often announce themselves in the form of a popup, or right at the bottom of a website. However, many internet users do not know that these cookies are just the tip of the iceberg, and that the majority of browser cookies interact with you completely without your knowledge. 

Although cookies can help you to have a more efficient and more personalised browsing experience, they also pose some privacy concerns. Cookies can store valuable information about you, which is then passed onto advertisers, and also potentially at risk of theft if you experience a cyberattack.

What Are Cookies Online?

A browser cookie is a tiny little code, or piece of data, that is stored on a web browser. Cookies store information such as items added in your shopping cart in an online store, or information about your preferences as a customer, and your past browsing activity. This data contains information about you, which is then often passed onto marketers and advertisers. 

Cookies can also be used to store your information for later use for your own convenience, including saving your address and payment details for future purchases in an online store.

How Do Cookies Work?

Whenever you visit a website, or take actions on a website such as clicking anything, a piece of data is transferred from that website to your web browser. You will end up picking up many different cookies from many different websites.

When you then return to a website that you have already been on, that website will read the cookies from your web browser. This website can now recall previous information about you, and also see what else you might have been doing on other websites.

Some cookies allow advertisers to track your browsing history on any webpage that contains their ads. If a webpage contains five ads, you will pick up five cookies, even if you never even click on them.

Are Browser Cookies Bad?

Cookies themselves are not harmful, as the data in cookies never changes. Cookies cannot infect your computer with viruses or other malware. However, some hackers hijack cookies. This gives them access to your browsing histories and any other data stored in cookies.  

What Are the 2 Types of Browser Cookies?

The two types of browser cookies are magic cookies and HTTP cookies.

“Magic cookies” are packets of information that are sent and received without changes. These types of cookies are no longer in use. They were the original type of cookies that gave rise to what we now use today.

HTTP cookies are the modern version of magic cookies, and are designed for internet browsing. They were originally used to help online stores to fix their overloaded servers, but are now used in a variety of ways.

What are Browser Cookies Used For?

Website Authentification

Whenever you visit a login page, a web server sends a cookie that contains a unique session identifier. This is remembered once a successful login occurs. 

Cookies are also used to remember your login information from the previous time you visited a certain website. Whenever you go on a website and see your login already filled in, this is due to a browser cookie.

Shopping Carts

Whenever you exit an online store and then return another day to find your items still in your cart, this is due to browser cookies. They remember what you had added last time, and allow these items back into your shopping cart.

Advertising

If you have ever looked at a product one time and then been constantly reminded of its existence with every subsequent ad that you have ever seen, this is due to cookies. 

This is known as “remarketing”. You pick up a cookie when you view an item, and this is sent to advertisers. These advertisers then use it to remarket this item back to you. The more times you see an item, the more likely you are to purchase it, which is why these cookies are so valuable to advertisers.

Personalisation

This is often used in online stores or streaming services such as Amazon. They learn what sort of things you like. This includes what genre of books or film you like, what sort of music you want to listen to.

This information is then used to show you things that you might be interested in. For example, if you have already listened to 5 albums by the same artist, your music streaming service will use that information to recommend you their sixth album.

How Do I Turn Cookies Off? 

Using incognito mode will not hide your browsing history from your school administrators or employers, but it will keep cookies from sticking to your browser. If your device does not have this option, you can also install an add-in to your browser, or consider using a VPN.

Does a VPN Prevent Browser Cookies From Sticking?

Cookies will still work with a VPN, as cookies are not inherently bad. However, your VPN will keep information a little bit more secure. VPNs don’t prevent cookies that are already stored on your compuer or internet browser, but using a VPN can help protect your identity and some VPN providers in the UK and further afield may offer specific add-ons and products which are designed to block or prevent browser cookies altogether.

Your VPN does not alter any web traffic being sent from your browser to the internet. However, your VPN can connect you with foreign servers and hide your IP address, which means that the tracking cookies will be fed some false information about you.