What are cookies on websites?

A cookie is a small text file a website saves in your browser to remember information between visits or pages. The useful kinds are why the web works smoothly: cookies keep you logged in so you do not re-enter your password on every page, remember what is in your shopping cart, save your language and site preferences, and hold your session together. These first-party cookies, set by the site you are actually visiting, are generally benign and necessary.

The privacy concern is third-party tracking cookies, set not by the site you are on but by advertising and analytics companies embedded in it. These follow you across different websites, building a profile of your browsing habits to target ads, which is why a product you glanced at once seems to chase you around the internet. This tracking is what fuels those endless cookie consent banners, driven by privacy laws like Europe's GDPR and California's CCPA that require sites to ask permission. You are not powerless: browsers let you block third-party cookies, clear cookies periodically, and use private or incognito mode, which discards them when you close the window, and major browsers have been phasing out third-party tracking cookies in favor of less invasive methods. Cookies themselves are not viruses or spyware and cannot run programs; they are just stored text, but the tracking economy built on them is a legitimate reason to manage them.