Exadata Smart Scan
This is a pretty cheesy presentation but it gets some interesting points about exadata and smart scan over in only 3 minutes.
Exadata offloads work to its storage servers which reduces the data that needs to travel over the network to the database servers.
For example, the storage servers filter out rows that are irrelevant to the querry before returning data to the db server for processing.
Another feature is data compresson allowing exadata machines to achieve data transfer speeds of up to 500Gb/s between db and storage servers.