According to Wikipedia:
A computer network is a set of computers sharing resources located on or provided by network nodes. The computers use common communication protocols over digital interconnections to communicate with each other. These interconnections are made up of telecommunication network technologies, based on physically wired, optical, and wireless radio-frequency methods that may be arranged in a variety of network topologies.
The Internet Protocol (IP) is the principal communications protocol being used on the Internet. As part of the OSI model, IP is the network layer protocol, or layer 3 protocol, in the Internet protocol suite. Devices form a network based on an IP address. Which is a 32-bit number that is used to identify a device on a network, at least when it comes to IPv4. In the future IPv6 will be used, which is a 128-bit number. NAT or Network Address Translation is used to translate the IP address of an internal network to an external IP address, which expands the number of available IP addresses on the Internet.
A subnet is a logical division of an IP network.
[HTTP][] is by far the most used application layer protocol on the Internet.