The methods by which companies track and identify its users vary from company to company.
But, some of the most widely used methods for tracking is through fingerprinting and cookies. Although cookies might seem like a very innocent name, cookies are the most widely used tracking method. Cookies are useful to the browsing experience. They store passwords, your search history, your site settings, and other settings make the browsing experience more convenient. However, cookies also serve to track information for companies. By saving your data such as browsing history, companies may sell the data and use it to cater user specific ads and content.
Another method of tracking users is by fingerprinting. Much like real fingerprints, every individual user on the internet has a unique setup. By taking into consideration the settings, hardware, apps, cookies, accounts synced, and IP address every individual user on the internet has a unique fingerprint. Fingerprinting a user is a more robust way of collecting information than cookies. Even if the user were to turn off cookies, there would be other ways to determine whose device is accessing the webpage.
By using methods such as described above, websites and companies are able to keep an eye on its users to log almost everything they do on a device with countless other tracking algorithms and methods. Although there is no sure way to keep companies and people from logging your information, there are ways to reduce the amount of information tracked. For one, by entering into your web browser setting, you are able to clear cookies and enable Do Not Track requests. Most web browsers are even deploying methods to try and reduce data tracking. Firefox for example is implementing settings to send do not track requests and to prevent as much user data from being collected.
Although some conveniences such as saved passwords and recommended content may be lost, having the piece of mind of privacy can be very valuable.