Router is a hardware device that connects two or more networks. It acts as a gateway between networks and is a specialized intelligent network device that reads the addresses in each data packet and decides how to transmit it.

IP-PBX is an enterprise-level telephone switching system based on IP networks, also known as an IP private branch exchange. Its core function is to convert voice signals into digital data packets using VoIP technology and transmit calls via Ethernet, replacing traditional circuit-switched PBX equipment to enable internal corporate communications, call management, and unified communication for multiple services.

IP telephone is a terminal device based on IP network. It can be directly registered to the IP-PBX or SIP server via Ethernet or Wi-Fi connection, supporting high-definition voice, video and status display, replacing traditional analog phones.

Servers and Storage which are the two core components in data centers and enterprise IT infrastructure. In simple terms, servers are responsible for "calculating", while storage is responsible for "storing".

"Firewalls" refers to a kind of cybersecurity system, which is used to monitor and filter the data traffic entering and leaving the network, and decides whether to allow or block based on preset rules.

Network switches are devices used to expand the network. They provide more connection ports for sub-networks, enabling the connection of more computers. Network switches are divided into wide area network switches and local area network switches.