High Availability is the configurable feature that should a host or vm goes offline, will initiate activity to bring that resource back online. Distributed Resources Scheduler is basically a load balancer on steroids! It is highly configurable with a variety of parameters such as affinity, anti-affinity, resource pools, resources shares, resource reserves, compatibility settings (CPU) etc. Storage vMotion is the ability to migrate a live vm from one LUN or volume on an array to another LUN or volume on the same or different array with no down time. Virtual Distributed Switch provides the ability of combining the Standard Virtual Switches from all of the Hosts in the Clusters into a single logical device. This improves consistency in naming port groups and also provides for advanced features which really come into to play when you start looking into NSX (VMware's SDN offering).