A computer network consists of two or more computing devices that
are connected in order to share the components of your network.

he modern data network has become a critical asset for many industries. Most basic data networks are designed to connect users and enable them to access various resources, 
All data networks are comprised of these elements, and cannot function without them.

The backbone of any network is the hardware that runs it. Network hardware includes network cards, routers or network switches, modems and Ethernet repeaters. Without this hardware, computers have no means of accessing a network. 

In order for the hardware to interact with the network, it needs software to issue commands. The primary form of networking software is protocols

Client devices are the computers and mobile devices connected to the network. Client devices are vital components of a network, as without clients requiring access the network is essentially pointless. In order to classify as a client device, a computer or mobile device must be able to connect to the network and utilize it. Depending on the network, client devices may also require specialized software to establish a connection.

Without connections, a network cannot function. The medium used to connect the nodes of a network varies with the type of network. 

Electromagnetic energy (includes electrical and magnetic fields) consists of power, voice, visible light, radio waves, ultraviolet light, gamma rays etc.

Transmission medium is the means through which we send our data from one place to another. The first layer (physical layer) of Communication Networks OSI Seven layer model is dedicated to the transmission media, we will study the OSI Model lat

 Key Terms to Know

 Mesh Topology

 Star Topology

 Bus Topology

 Ring Topology

 Tree Topology

A network protocol  defines rules and conventions for communication between network devices. Network protocols include mechanisms for devices to identify and make connections with each other, as well as formatting rules that specify how data is packaged into sent and received messages.

Internet Protocols

The Internet Protocol (IP) family contains a set of related (and among the most widely used) network protocols. Beside Internet Protocol itself, higher-level protocols like TCP, UDP, HTTP, and FTP all integrate with IP to provide additional capabilities. Similarly, lower-level Internet Protocols like ARP and ICMP also coexist with IP. In general, higher-level protocols in the IP family interact more closely with applications like web browsers, while lower-level protocols interact with network adapters and other computer hardware.

Thanks to Wi-Fi, Bluetooth, and LTE, wireless networks have become commonplace. Network protocols designed for use on wireless networks must support roaming mobile devices and deal with issues such as variable data rates and network security.

Routing protocols are special-purpose protocols designed specifically for use by network routers on the internet. A routing protocol can identify other routers, manage the pathways (called routes) between sources and destinations of network messages, and make dynamic routing decisions. Common routing protocols include EIGRP, OSPF, and BGP.