1. A group of computers that are connected in some fashion. Most school networks are known as LANs, or Local Area Networks, because they are networks linking computers in one small area. The Internet could be referred to as a WAN, or a Wide Area Network, because it connects computers in more than one local area. It is also a series of points connected by physical or virtual connects. From Glossary of Distance Education and Internet Terminology

2. Any time you connect 2 or more computers together so that they can share resources, you have a computer network. Connect 2 or more networks together and you have an internet. From Matisse