SOA is an architectural style whose goal is to achieve loose coupling among interacting software agents. A service is a unit of work done by a service provider to achieve desired end results for a service consumer. Both provider and consumer are roles played by software agents on behalf of their owners.

This sounds a bit too abstract, but SOA is actually everywhere. Let's look at an example of SOA which is likely to be found in your living room. Take a CD for instance. If you want to play it, you put your CD into a CD player and the player plays it for you. The CD player offers a CD playing service. Which is nice because you can replace one CD player with another. You can play the same CD on a portable player or on your expensive stereo. They both offer the same CD playing service, but the quality of service is different.

The IoD Strategy, the Pervasive Information Fabric using agents and multi-agents and the E2EIoD processes are a "Storage-based" approach to SOA. The "Quality of Service (QoS)" difference is pre-determined by the Service Level Agreement (SLA) process. The SOA is driven by the SLA's and both are based on the Unit of Information Content.
Not the Unit of Technology storing it.