The internet consists of edges and nodes. Every computer out there is a node and every cable is an edge. Wireless communications have an invisible cable, which is called air:

As you can see in the preceding diagram, we can visualize internet as a cloud. We don' t really have to understand what's in there. Your Internet Service Provider (ISP) provides you with your internet connection. Thus, you usually have a router in your home. Since there are billions of nodes connected to the internet communicating over protocols and sending/receiving hundreds of messages, there must be a way of identifying who is who. This means that the router must have a unique identification, like the address in your house. This address is called the IP address or Internet protocol and there are two protocols. The old and classic one is version4 and the new one is version6. No further explanation is needed for this, just remember that every home has a router and every router has a unique IPv4 address. So now everyone from outside your house knows that every packet in your IPv4 address will reach your router.