A network switch operates at the data link layer (Layer 2) and is used to connect devices within a LAN, directing data to its intended destination.
An IP address is a unique address that identifies a device on the internet or a local network.
Dynamic Host Configuration Protocol (DHCP) is used to automatically assign IP addresses and other network configuration parameters to devices on a network.
A router operates at the network layer (Layer 3) and is responsible for routing data between different IP networks.
A subnet mask is used to divide an IP address into a network and host portion, determining which part of the address refers to the network and which part refers to the specific device.