Cookies are text files that your web browser stores on your computer. When you visit a website, it might want to know a little about you in case you come back again (maybe you've selected some preferences or logged into your account). In essence, cookies save you the trouble of reentering the information later.
There are some privacy concerns about all this, though. Keep reading to learn more about them.
You might have heard that Cookies have something to do with improving your experience. They're often used to tailor site content to your own preferences – like storing items in your online shopping cart between sessions, for example.
In this article, we'll take a deep dive into cookies: the good, the bad, and the ugly.
What is a cookie?
But why do computers store that file? Well, there are a few different reasons. Broadly speaking, cookies help a web server to remember you. You'll do something on the website (it could be anything from switching to dark mode to logging in), and your computer makes a note of this. Then, the next time you visit, it hands the information back to the website.
Types of cookies
What are cookies made of?
The data you pass to the site when you access it. If you log in successfully, the cookie will be created.
Nothing too sophisticated in there, right? There's minimal personal information (and it isn't shared with other domains). Those numbers you see are timestamps – one tells you when the cookie was issued, and the other tells you when it expires. You also see the issuer, your username, your role (user or moderator), and a string related to authentication.
Cookies typically have this key-value pair system. Note that many sites nowadays will provide a user ID. Once an individual visits, the server checks its database for any information it has on them and tailors the user experience accordingly.
If you fire up the prompt to clear your browsing history, you generally get the option to clear cookies, too. When you do this, you don't cause any major damage to site data. You'll notice, however, that you'll need to reenter any login information when you return to the sites that provided you with the cookies.
The dark side of cookies
From our example above, you can see that there's nothing inherently evil about a cookie. Most of the time, first-party cookies work to streamline your experience. That said, you should be aware of the potential privacy ramifications that come with cookies. Ultimately, they can collect personal data – so much so that tightening data protection regulations like the General Data Protection Regulation (GDPR) require that many websites comply with their guidelines.
Third-party cookies can be particularly problematic for those conscious of their digital footprint. You've undoubtedly felt unsettled by advertisements that follow you around the web, based on what you've been reading or watching. Ever seen those social media "share" buttons on a website? Even if you don't interact with them, they can parrot information about your activity back to the provider.
Getting rid of cookies
Many browsers now block them for you by default (check your browser settings). Failing that, there are a handful of plugins and browser extensions you can use to prevent unwanted tracking, such as Privacy Badger and Ghostery.
Cookies shouldn't necessarily be viewed as the bogeyman of the Internet. If you've checked out our other articles in the Security category, you'll know that it's very easy to unwittingly leak personal information.
First-party cookies are part and parcel of the online landscape today, and for good reason – they improve the quality of your experience by storing information on your machine. Third-party cookies exist not so much for your benefit, but rather for that of data mining entities. By leveraging tools available in your browser, however, you can trivially block the majority of them.