An IP (Internet Protocol) address is basically how your computer or device is identified on the Internet. Any computer or device that is connected to the Internet must be assigned a logical IP address, either from your ISP (Internet Service Provider) or from your local router’s Dynamic Host Configuration Protocol (DHCP) server.
You can think of an IP address like a vehicle license plate. Every vehicle on the road (legally) has a license plate that is registered with the local DMV. The plate is like the car identification card, allowing someone (usually a police officer) to look at the plate and get all sorts of information about the owner of the vehicle the plate is registered to. An IP address works the same way. Every computer that browses the web needs to have some sort of identifying IP address, whether it’s an IP assigned to the actual computer, the router the computer is connected to, or the proxy server the computer connects to. This address is what identifies a computer on the web like a license plate is what identifies a vehicle on the road.
A MAC (Media Access Control) address, on the other hand, is the physical address of the NICs (Network Interface Cards) in your computer (sort of like a serial number). In transmission networks, such as Ethernet, the MAC address uniquely identifies each node (workstation/computer) for the delivery of specific packets. If you enjoy analogies, you can compare a NIC’s MAC address to a vehicle’s VIN number. The MAC identifies physical network hardware much like a vehicle’s VIN identifies a specific vehicle.
The reason I chose a vehicle for my analogies is to help readers understand that a dynamic IP address can change in the same way that a vehicle’s license plate number can. But a MAC address (under most circumstances) cannot be changed any more than a vehicle’s VIN can be changed.
However, a static IP address is an IP address that you keep constant and never change (and you usually have to pay a fee). Having a static IP is useful for those running servers or any type of equipment where the IP address needs to always stay the same.