Comprehensive and Detailed in Depth Explanation:

A data center comprises core infrastructure components as defined in the HCSA-Sales-IP Network V6.0:

Server (A): The computational backbone of a data center, hosting applications and services.

Data network (B): Provides connectivity between servers, storage, and external systems.

Video security system (C): While security is important, it is not a core structural element of a data center; it's an auxiliary system.

Storage system (D): Essential for data retention and retrieval.

Storage switching network (E): Facilitates high-speed connectivity between storage devices and servers (e.g., SAN or NAS).

Thus, A, B, D, and E are the primary elements, while C is excluded as a supplementary feature.