Cisco Systems, Inc. is an American multi national technology conglomerate headquartered in San Jose, California, in the center of Silicon Valley, that develops, manufactures and sells networking hardware, telecommunications equipment and other high-technology services and products. Through its numerous acquired subsidiaries, such as OpenDNS, WebEx, Jabber and Jasper, Cisco specializes into specific tech markets, such as Internet of Things (IoT), domain security and energy management. Cisco is the largest networking company in the world. The stock