Which technology is used to improve web traffic performance by proxy caching?

Cisco Web Security Appliance (WSA) functions as a secure web gateway and includes robust proxy caching features to store frequently accessed web content, thereby reducing bandwidth usage and improving response times for clients.

Cisco Firepower is a Next-Generation Firewall (NGFW) and Intrusion Prevention System (IPS) primarily focused on threat detection and prevention, not web traffic caching for performance.

Cisco FireSIGHT Management Center is a management platform for Firepower devices, providing visibility and control, but it is not a technology for proxy caching.

Cisco ASA (Adaptive Security Appliance) is a firewall, VPN concentrator, and intrusion prevention system, designed for network security and access control, not web content caching.