1) The Internet is the global system of interconnected computer networks that use the Internet protocol suite (TCP/IP) to link devices worldwide. It is a network of networks that consists of private, public, academic, business, and government networks of local to global scope, linked by a broad array of electronic, wireless, and optical networking technologies.
2) The Internet of things is the inter-networking of physical devices, vehicles (also referred to as "connected devices" and "smart devices"), buildings, and other items—embedded with electronics, software, sensors, actuators, and network connectivity that enable these objects to collect and exchange data.In 2013 the Global Standards Initiative on Internet of Things defined the as "the infrastructure of the information society"
3) If you use two or more operating systems you probably will want to exchange data between them at some point. If they are on separate computers and the computers are networked, you can use programs like ftp (available for most, if not all, operating systems) or (between Unix-like systems) rcp . Between non networked computers you can use kermit(also available for most, if not all, operating systems) to transfer data via modem or over a serial line connection.