Third-party cookies are typically set by service partners that you include on your website. For example:
A "Pin it" button will store a cookie on your visitor's device that can later be accessed by Pinterest to identify the visitor's browsing history
Google AdWords will store a cookie on your visitor's device to allow AdWords to identify the ad campaign the visitor came from or other relevant information
Some regulations require that you block third-party cookies prior to user consent. If you have a consent banner but aren't blocking third-party cookies, you may not be compliant.
Script blocking methods
Automatic blocking (recommended)
Use Termly's Auto Blocker to automatically detect, block, and enable or disable third-party tracking mechanisms based on your user's saved preferences