IP address

A unique 32-bit number used to identify device on the internet network.

IP address mask

Bit mask defining range of addresses which could be used within network. For example 255.255.255.0 mask with 192.168.0.0 network allows 254 addresses from 192.168.0.1 to 192.168.0.254. Note that 192.168.0.255 and 192.168.0.0 are first and last addresses on the network and are called broadcast addresses. They are reserved and shouldn't be used due to potential conflicts with legacy equipment.

Small business/home network

Network of multiple devices present inside or within the close vicinity of home/business. Typically managed by one modem and router with address space

Router IP address

Unique IP address used by router to identify itself on the network. Example addresses used by routers are 192.168.1.1, 192.168.0.1, 192.168.1.254, 10.0.0.1.

Router

Device which routes network packets within local network and external networks.

WAN port

Wide-area network port. Ethernet port on the router typically used to connect it to the modem. On bigger networks it could be used to connect to other routers.

Modem

Device used to connect local network to internet. Could also have some functions of router.

Wi-Fi

Wireless protocol for connecting devices via radio band.

Port forwarding

Forwarding of external network packets directed to a port into a specific IP address within local network.