KMS is a legitimate technology used by large organizations to activate hundreds of computers simultaneously via a local server. Unauthorized activators like KMSAuto or KMSPico simulate this server on your personal machine: Microsoft Key Management Service (KMS) - GWDG - docs
Bagas31 KMS Activator appears to be a specific KMS activation tool developed by a person or group, possibly named "Bagas31". This tool likely aims to activate Microsoft products using KMS activation methods. kms activator bagas31