A warm site is a type of disaster recovery site that has some pre-installed hardware, software, and network connections, but not as much as a hot site. A warm site also has some backup data, but not as current as a hot site. A warm site requires some time and effort to become fully operational in the event of a disaster. A hot site is a disaster recovery site that has all infrastructure and live data, and can take over the primary site's operations immediately. A cold site is a disaster recovery site that has no infrastructure or data, and requires significant time and resources to set up. Reference:
https://www.enterprisestorageforum.com/management/disaster-recovery-site/
https://www.techopedia.com/definition/3780/warm-site