Which functionality does a Control layer provide in a software-defined networking architecture?

What does the "X" represent in the exhibit?

A consumer is interested in a service that provides multiple operating systems and programming frameworks for application development and deployment.
Which recommended cloud service model will meet these requirements?

Which technology combines NAND flash memory into a hard disk drive and is a single, integrated device incorporating both types of storage?

A company is using an intrusion detection and prevention system (IDPS) to scan and analyze intrusion events.
Which IDPS technique uses a database that contains known attack patterns?