Many patches or "keygens" that instruct users to add these lines are disguised malware. They may open backdoors into the system.
This is a domain name previously used by Adobe's software ecosystem (especially during the Creative Suite eras, such as CS4, CS5, and CS6). When a user launches an Adobe application, the software attempts to contact this server to verify that the installed serial number or license is valid. The Role of the Hosts File 127.0.0.1 activate.adobe.com
If this entry was added by a malicious actor or you want to restore proper licensing, you must remove it from the hosts file: Many patches or "keygens" that instruct users to