In vSphere 6.7, VMs can be moved from one host or storage to another using hot or cold migration. Wherever possible, hot migration is the preferred option to use to avoid service disruption because it performs a live migration of the VMs:

• Hot migration: A powered-on VM can be moved to a different host or datastore without service disruption using the vMotion or Storage vMotion features.
• Cold migration: This is the migration of a powered-off or suspended VM. You can move associated disks from one datastore to another and VMs are not required to be on shared storage. A cold migration can be performed manually or by scheduling a task.

There are two types of vMotion:

• Compute vMotion (otherwise known as standard vMotion) is responsible for migrating active state (the content of VM memory) between two ESXi hosts
• Storage vMotion (SvMotion) is responsible for the migration of the storage resources between two different datastores