Handle
VkPhysicalDevice
Opaque handle to a physical device object
Vulkan separates the concept of physical and logical devices. A physical device usually represents a single complete implementation of Vulkan (excluding instance-level functionality) available to the host, of which there are a finite number. A logical device represents an instance of that implementation with its own state and resources independent of other logical devices.
Physical devices are represented by VkPhysicalDevice handles:
VK_DEFINE_HANDLE(VkPhysicalDevice)