Web bug
A web bug is a 1x1 pixel image used to track a user reading a web page or e-mail. After the GIF (Graphics Interchange Format) image loads, the time loaded, how long it was viewed, the IP address, and the browser used can be tracked. For example, the file __utm.gif is a small image file loaded on web pages with Google Analytics to help keep track of page views.
A web bug may also be called a 1-by-1 GIF, ad pixel, hidden pixel, invisible GIF, pixel tag, tracking bug, tracking pixel, or web beacon.
To prevent a web bug from tracking Internet activities, turn off cookies and see if your browser has web bug-blocking add-ons. To prevent a web bug from tracking e-mails, most e-mail clients today warn users when an e-mail is attempts to load images, which lets you accept or prevent images from loading. You can also turn off HTML (HyperText Markup Language) e-mails or only accept plain-text e-mails.
A web bug is what allows a company like Facebook or Tiktok to track you even if you have never installed their app or used their service. If these companies or another ad company has these web bugs on websites, they can track you. However, they may not have as much details (e.g., know your name), if you've never installed their app. Unfortunately, information they may not have is often purchased from another company.
Advertising terms, Cookie, Security terms, Spyware, Tracking, Web