Data networks are systems that connect computers and devices to share information and resources. They enable communication between users and allow for the transfer of data, such as files, emails, and multimedia. Common types of data networks include local area networks (LANs), wide area networks (WANs), and the Internet, which is the largest network connecting millions of devices worldwide. These networks use various technologies and protocols to ensure data is transmitted efficiently and securely. Key components of data networks include routers, which direct data traffic, and switches, which connect devices within a network. Understanding data networks is essential for effective communication in today's digital world.