If you read the news every now and then, you have probably heard of cookies on the internet. But what actually is a Cookie?
When cookies were invented they basically were little documents containing helpful information about you and your preferences. For Example:- Assume that you are trying to select a certain language for a website you would visit. At that time you would tell the website that I would like to view your website in say English. The website then sends that information to a little document called as a cookie on your computer.
So thus the next time when you try to visit that website, then it would be able to read the cookie it saved earlier. That way the website could remember your language and let you view the website in English, without you having to select your language again.
Really easy right? But wait! the cookies are not limited to remembering just your language. But in fact, a cookie can contain pretty much any kind of information; it can contain the time you visited a website or it can contain the items you added to your shopping cart. It can even contain all the links you clicked on a certain website, much like having a track on the internet.
A cookie can only contain so much text, but apart from its size, the possibilities are endless. What exactly is saved to a cookie is up to the creator of the website you are visiting. Now, in contrast to the stuff a cookie can contain there, there are limits to who can read your cookies. Imagine that you first visit the website that we talked about earlier and you told that website that your language is English. This is then saved to a cookie on your computer. If you would then visit a different website later, then the latter would not be able to read the cookie from the first website. In simple words, we can say that only the same website that saves information to a cookie can access it.
Since the beginning of cookies, the popularity of these clever little helpers exploded and they gradually evolved into a more complex, yet essential part of the internet. During the evolution, the amount of data cookies contained started to grow. At first, they contained just a few preferences like your language and maybe your preferred layout for a website. But soon the developers realized that the more information they could store about you, the better you could suit your needs. So cookie started containing more and more data and eventually started pushing their size limitations.
Subsequently, developers came up with a clever workaround i.e. what if they would simply store a unique id in a cookie on your computer and save the rest of the data in their own system? That way they could save the unlimited amount of the data. The cookie would simply serve as an identifier for your computer, using which website can recognize you and look up your data in its own system.
This was the first leap towards so-called third-party cookies. As mentioned earlier only the same website that saved data to a cookie can access it later. But one website can actually contain bits of another website. These bits and pieces of other websites embedded in the website you are visiting are actually able to access cookies they saved to your computer earlier.
Imagine visiting a new website, apart from news articles, many news websites contain a couple of ads. These ads are in most of the cases bits of other websites, embedded into the news website. Now the news website you are looking at may not have saved any cookies to your computer and thus know nothing about you. But where do the ads come from?
It is not unlikely that the ads on the news website are embedded from the same website as the ads on another website you visited earlier. In fact, you may visit dozens of websites with ads which are all embedded from the same website.
So what does this means? This means that if the website the ads come from has saved a cookie to your computer earlier, it cm identify you and save information about you through other websites. So while you are reading that news website, shopping for new items, looking up for some information or reading a blog etc. the ads on those websites can identify you, look up your information in their own system and dynamically show ads that you are most likely to be interested in while simultaneously solving information about what you are doing online.
So Is this a bad thing? Are the cookies dangerous? That depends really upon the creators of a website to determine what information they do and do not store and most importantly what they use that information for.
