Tracking cookie is a sample of text dropped on your browser once you visit a website. Tracking Cookies collect user data, such as activity on websites, browsing history, location, IP addresses, and purchase history. However, before tracking visitors, websites must inform visitors about tracking and they usually do that by putting a Cookie Banner in place. It carries the necessary information for a website to be compliant with data privacy laws and also gives the option for users to opt out of tracking.

Tracking Cookies can also come through widgets, ads, or other elements of the website. For example, Facebook can track users if a website puts a Facebook widget onto its homepage – this is a usual practice for most websites that share their social media banners.

If you're wondering why Tracking Cookies collect information, there can be many reasons: website owners may use the data for analytics, or to personalize your browsing experience. In that case, Tracking Cookies are a memory box that stores your information to improve browsing experience. If you accept cookies during your first visit to a particular address, the website then stores your preferences and keeps them until your next visit to show personalized ads and suggestions to you. 

However, such ads can become annoying over time, and you may want to get rid of them. Therefore, websites must provide their users an option to opt-out of tracking cookies at any time possible to comply with the latest data privacy laws in the world.