The Internet remembers you
When you sit and search the Internet, it’s a bit like shouting in a tunnel. All the information you provide will be returned to you in the form of personalized search results. This means that the search engine often shows you content that it thinks you like and agree with, and not things that might influence you to believe otherwise.
The Internet is also full of advertising. When you visit various websites, advertisements will “pop up”. Often without you having asked for it, and it often matches your interests and online shopping habits. If you have shopped online, the websites will “remember” that and try to entice you to buy more.
Information cookies, or cookies, store login details and register where you are and what websites you visit. Then this information will be thrown back at you as an echo the next time you surf the web. Why do you think they are called cookies?