- Para-virtualization mode, where the virtual machine knows it's being
- virtualized and as such there is no need for hardware emulation.
+ (Xen) Para-virtualization mode, where the virtual machine knows it's
+ being virtualized and as such there is no need for hardware
+ emulation or virtualization.
+
+ SoR
+ *State of Record*. Refers to values/properties that come from an
+ authoritative configuration source. For example, the maximum VCPU
+ over-subscription ratio is a *SoR* value, but the current
+ over-subscription ration (based on how many instances live on the
+ node) is a :term:`SoW` value.
+
+ SoW
+ *State of the World*. Refers to values that describe directly the
+ world, as opposed to values that come from the
+ configuration. Contrast with :term:`SoR`.
+
+ tmem
+ Xen Transcendent Memory
+ (http://en.wikipedia.org/wiki/Transcendent_memory). It is a
+ mechanism used by Xen to provide memory over-subscription.