Let’s break down the term to understand the concept of Local Area Network or LAN as abbreviated.
Network, typically means connection between entities or end systems or computers or computing devices. Area, emphasize that there must exist some geographical boundaries over which the network is spread. Local, means approachable or in vicinity i.e. the area where the network is spread must be limited and measurable in metres.
A LAN is a network of interconnected devices, these devices may consist of End Systems (Computers, Laptops, Mobiles, Tablets, etc.) and Networking Components (Routers, Switches, Hubs, etc.) through cables (wired) or through frequency (wireless).
The networking devices such as routers and switches are known as active Network Components, whereas, the devices such as cables, RJ 45 connectors are known as passive network components.
Since, the devices forming part of a LAN are interconnected, they can seamlessly communicate with each other. Communication means they can send messages to each other or they can share files with each other.
The end systems are connected with each other through cables via a switch. The connectivity between devices through switch takes a form of a topology generally in the form of a star, ring or mesh. In star topology each device is independently connected to a switch with a single wire connection. In ring topology the cabling start from a device connects to another end device, this end device in turn is connected to another end device and so on. The last device in this chain is connected back to the first end device, thus, forming a ring. Mesh topology is a combination of both i.e. each device has a connectivity with a switch and with another end device.
Among the topologies, Mesh is the most reliable with high Fault Tolerance i.e. it is the most reliable in terms of failure of the network if one of the links (cables) is down or broken.
A Cat-6 Cable is usually used to connect which is a set of twisted pair copper wire. The cable could be terminated at one end with a RJ-45 connector and another end may be punched in a jack panel (a wall mounted rack) or I/O box (fixed on a wall). A cable may also be terminated at both ends with a RJ-45 connector, such cables are short in lengths and called patch cords usually used to connect a end system at one end and a I/O box at other end to bring the device on network.
The network when extended beyond the limits in Metres and could be measured in Kilometres with a large number of end systems, network components forms a WAN or Wide Area Network.